Surgical Instrument Arrangement And Drive Train Arrangement For A Surgical Instrument, In Particular A Robot-Guided Surgical Instrument, And Surgical Instrument

ABSTRACT

A surgical instrument arrangement has a modular motor drive unit which has a drive arrangement having at least one output element, an instrument shaft that can be detachably connected to the drive unit, and a drive arrangement having at least one input drive element. The output drive arrangement and the input drive arrangement can be coupled to each other by a mechanical interface that has at least one single-sided linkage, a pin, and a cut-out, wherein the pin can be radially expanded in the cut-out. Alternatively, a gap may be formed between the pin and the cut-out, which gap is wavy in the radial direction, and in which a radially displaceable, axially fixed intermediate element arrangement is arranged. The surgical instrument arrangement may also include a sterile barrier, which is provided to envelop the drive unit and to be arranged between the drive unit and the instrument shaft.

CROSS-REFERENCE

This application is a continuation of International Patent ApplicationNo. PCT/EP2013/001917, filed Jun. 28, 2013 (pending), which claimspriority to DE 10 2012 013 242.5 filed Jul. 3, 2012, DE 10 2013 004230.5 filed Mar. 11, 2013, DE 10 2013 004 487.1 filed Mar. 14, 2013, DE10 2013 005 493.1 filed Mar. 28, 2013, and DE 10 2013 007 761.3 filedMay 6, 2013; and is related to U.S. patent application Ser. No.14/579,172 (Pending), U.S. patent application Ser. No. 14/579,221(Pending), U.S. patent application Ser. No. 14/579,296 (Pending), U.S.patent application Ser. No. 14/579,341 (Pending), U.S. patentapplication Ser. No. 14/579,398 (Pending), U.S. patent application Ser.No. 14/579,465 (Pending), and U.S. patent application Ser. No.14/579,597 (Pending), each filed Dec. 22, 2014, the disclosures of whichare incorporated by reference herein in their entirety.

TECHNICAL FIELD

One aspect of the present invention relates to a surgical instrumentassembly, a manipulator surgical system with a manipulator-guidedinstrument assembly of this type, and a method for equipping amanipulator thereof.

BACKGROUND

By way of example, a manipulator surgical system having amanipulator-guided surgical instrument is known from EP 1 015 068 A1,the degrees of freedom of which are actuated by a drive train assemblyin the manipulator, which, in particular, makes the attachment of theinstrument to the manipulator more difficult with respect to sterilityrequirements.

DE 10 2009 060 987 A1 discloses a surgical manipulator instrument havingits own drive unit for actuating degrees of freedom for the instruments,which has a mechanical interface with a coupling element that engages inan undercut protrusion of a further coupling element, without addressingsterility requirements.

SUMMARY

An object of one aspect of the present invention is to make available animproved surgical instrument.

A further aspect of the present invention relates to a drive trainassembly for actuating at least one degree of freedom of an end effectorof a surgical instrument, in particular a robot-guided surgicalinstrument, a drive module and an instrument shaft of such aninstrument, an instrument having such an instrument shaft and/or drivemodule, a manipulator assembly having at least one such instrument,which is guided by a manipulator, and a method and a guidance means forguiding such an instrument, in particular its drive and/or a manualteleoperation means.

A robot-guided minimally invasive surgical instrument has, in general,an instrument shaft. With an instrument shaft partially inserted by atrocar, a distal, or intracorporeal instrument shaft end can still bemoved by the robot in a maximum of four degrees of freedom (three axesof rotation by the trocar point and one translation in the direction ofthe shaft axis).

In order to have available more degrees of freedom in a minimallyinvasive operating field, the mounting of an end effector in anarticulated manner on the distal end of the instrument shaft, andadditionally, the actuation thereof by a drive train assembly, is knownfrom WO 2009/079301 A1. By way of example, a clamp can be closed, or anendoscope optics can be reoriented, in this manner.

In order to give a teleoperator, who operates the surgical robot, ahaptic feedback from the operating field, WO 2009/079301 A1 proposesthat a force-torque sensor having six axes be disposed between theinstrument shaft and the end effector bearing.

One disadvantage of this solution can be illustrated on the basis ofFIG. 34: an instrument shaft 20 is shown there, as shall be described ingreater detail below, on which an end effector, in the form of a clamphaving two blades 2.1, 2.2, is disposed. The blade 2.1 can be adjustedin its rotational degree of freedom q₁ in relation to the instrumentshaft by means of two drive trains 21, 22 running in oppositedirections, the blade 2.2 can be adjusted in a corresponding manner. Ifthe clamp engages with a lumen (not shown), the reaction forces F_(E1)and F_(E2), respectively, act thereon. These forces do not exert anyforces in the instrument shaft 20 in the constellation depicted in FIG.34, because their resultant force disappears. Accordingly, aforce-torque sensor, such as that proposed in WO 2009/079301 A1, cannottransmit feedback pertaining to the forces exerted by the clamp to theteleoperator, because it does not register any forces or torques in theinstrument shaft from the actual exerted clamping forces F_(E1), F_(E2).

An object of one aspect of the present invention is to make available animproved surgical instrument, and/or to improve the control thereof.

A further aspect of the present invention relates to a surgicalinstrument, in particular a robot-guided surgical instrument, having aninstrument shaft with at least one degree of freedom and a drive unitfor the actuation thereof, as well as an instrument shaft and a driveunit.

A robot-guided surgical instrument having four dive units is known fromWO 2011/143022 A1, which are arranged on a base plate in the manner ofpie slices, and each have numerous drive modules. The drive modules eachhave numerous displaceable or rotatable output drive links for actuatinginput drive links of an instrument shaft connected to the drive unit.

The drive units can each be actively telescoped in relation to the baseplate, in order to retract or extend their instrument shaft through acommon guide cannula. The output drive links are distal in relation tothe input drive links, or are in front thereof in a coupling device,which is parallel to the longitudinal axis of the instrument shaft, andare elastically pre-tensioned in this distal direction, in order toensure contact without play.

An object of one aspect of the present invention is to make available animproved surgical instrument.

A further aspect of the present invention relates to a surgicalinstrument, in particular a robot-guided and/or minimally invasivesurgical instrument, as well as a drive module and an instrument shaftfor such an instrument, and a method for the connection thereof.

By way of example, a robot-guided, minimally invasive instrument havingan instrument shaft, is known from WO 2011/143022 A1, which is insertedinto the patient by a robot through a natural or artificial little hole.In order to actuate intracorporeal degrees of freedom, in particular foran end effector, an extracorporeal drive module is releasably connectedto the instrument shaft.

An object of one aspect of the present invention is to make available anadvantageous surgical instrument.

According to one aspect of the present invention, a surgical instrumentassembly, in particular a manipulator-guided surgical instrumentassembly, has a modular motor drive unit, which has an output driveassembly with one or more output drive elements. In the present case, anoutput drive element is understood to be, in particular, a single- ormulti-part element or component, which can be directly or indirectlyactuated, or adjusted in an adjustment direction, respectively, by amotor, in particular an electric motor, of the drive unit, and isprovided for actuating a degree of freedom of the instrument. The driveunit can be provided with power and/or controlled in an embodimentfunctioning in a wireless manner, or having wire connections.

The instrument assembly furthermore has an instrument shaft, which isprovided in one embodiment for being partially inserted in a patient, inparticular through a hole for minimally invasive surgery, in particularalso for endoscopy. The instrument shaft can be designed such that it ispartially or entirely stiff or flexible, and/or have an end effector, inparticular a scalpel, a scissors, forceps, clamp, an optical recordingand/or lighting means, in particular a fiber optics end, a CCD chip (aso-called “chip-on-the-tip” endoscope), an LED, or suchlike. In thisrespect, it can also represent an actuatable, in particular a bendable,endoscope of an instrument shaft, as set forth in the present invention.An instrument shaft as set forth in the present invention has, ingeneral, one or more degrees of freedom, in particular one or moredegrees of freedom for positioning, in particular for orienting, and/orfor actuating, an end effector. In a further development it has two,three, or more degrees of freedom, in particular a rotational degree offreedom, for orienting and/or one or more, in particular a maximum ofone, degree of freedom for actuating, in particular for opening orclosing, an end effector. For the actuation, it has a drive assemblyhaving one or more input drive elements. In the present case, an inputdrive element is understood to be, in particular, a single- ormulti-part element or component, which can be directly or indirectlyactuated, or adjusted in an adjustment direction, respectively, by meansof an output drive element allocated thereto, and is provided foractuating a degree of freedom of the instrument. For this purpose it canbe coupled to the end effector, in particular in a unidirectional orbidirectional manner, mechanically in one embodiment, in particular bymeans of one or more pull cables, rods, or gearwheels, hydraulically,pneumatically, or suchlike, wherein a unidirectional coupling isunderstood, in particular, to be such a coupling by means of which thedegree of freedom can be actuated by an adjustment of the input driveelement in only one sense of direction, by means of a pull cable in onlyone pulling direction, for example, and a bidirectional coupling isunderstood to mean, accordingly, a coupling, in particular, by means ofwhich the degree of freedom can be actuated by an adjustment of theinput drive element in opposite directions, by means of a push rod, forexample, in a pulling and a pushing direction.

The instrument shaft can be releasably connected to the drive unit, andthe output drive assembly and the drive assembly can be coupled to oneanother, by means of a mechanical interface. In a further development,the instrument shaft is releasably connected to the drive unit, and theoutput drive assembly and the drive assembly are coupled to one anotherby means of the mechanical interface. The instrument assembly is thenalso referred to, in short, as the instrument. In one embodiment,however, two or more different drive units and/or two or more differentinstrument shafts can also be provided, which can be selectivelyconnected to an instrument shaft or a drive unit, and which can differ,in particular, in the number of actuatable degrees of freedom. For amore compact depiction, in the present case an instrument assembly isreferred to in general as a set of one or more drive units and one ormore instrument shafts, which can be, or are, releasably connected toone another.

The instrument assembly, or the instrument, respectively, in particularthe drive unit or the instrument shaft, is releasably attached to amanipulator in one embodiment, and for this purpose, can have acorresponding attachment interface in a further development.Accordingly, one aspect of the present invention relates to a method forequipping a manipulator, wherein one drive unit and one instrument shaftare releasably connected to one another, and their output drive assemblyand the drive assembly are coupled to one another by means of themechanical interface. The manipulator can have one or more, inparticular at least six, preferably seven or more, degrees of freedom inone embodiment, for guiding (redundantly) the instrument, in particularfor positioning its end effector in a patient.

One factor of the present invention relates to the design of themechanical interface, by means of which the output drive and driveassembly can be, or are, coupled to one another.

According to one aspect, this interface has, in each case, one one-sidedlinkage between one or more pairs of output and input drive elementsallocated to one another. A one-sided linkage, or coupling,respectively, is understood in the present case to mean, in particular,as is typical in mechanical engineering, that a movement of the one ofthe output drive and input drive elements in one direction, or in onesense of direction, respectively, causes a positively driven movement ofthe other of the output drive and input drive elements, and a movementof the one of the output drive and the input drive elements in theopposite direction, or the opposing direction, respectively, conversely,does not cause positively driven movement of the other of the outputdrive and the input drive elements. In particular, a one-sided linkagecan be characterized in that only pressure forces, and no tractiveforces, can be directly or indirectly transferred between the outputdrive and the input drive elements, wherein in the present case, for amore compact depiction, anti-parallel pairs of forces, i.e. torques, arealso referred to in general as forces. A one-sided linkage canaccordingly be characterized in that only a torque in one direction canbe directly or indirectly transferred between an output drive and aninput drive element, whereas in the opposite direction, at leastsubstantially, no torque can be transferred. Accordingly, a two-sidedlinkage is understood, in the present case, to mean, in particular, thatmovements in opposing directions of the output drive or input driveelements are transferred in a positively driven manner to the respectiveother element, in particular, direct or indirect pressure and tractiveforces, or torques in opposing directions, respectively, can betransferred between the output drive and input drive elements.

A one-sided linkage can act advantageously via a sterile barrier. Inparticular, in one embodiment an output drive element and an input driveelement allocated thereto can be disposed on opposite sides of a sterilebarrier, and be in contact therewith, wherein at least one of the outputdrive and input drive elements is not connected to the sterile barrier,or can be detached therefrom, respectively. In this manner, a sterilebarrier can be disposed between the drive unit and the instrument shaftin a simple and compact manner.

According to one aspect, the mechanical interface, by means of which theoutput drive and drive assembly can be coupled, or are coupled,respectively, to one another, has at least one cut-out in each case,that is formed in an element of one or more pairs of output drive andinput drive elements allocated to one another, and one pin in each case,which is formed on the other element of this pair, and which can be, oris, respectively, inserted in this cut-out. In particular, one or moreoutput drive elements can thus have one or more pins in each case, andthe input drive elements allocated thereto can have correspondingcut-outs. Likewise, one or more input drive elements can each have oneor more pins, and the output drive elements allocated thereto can havecorresponding cut-outs.

According to one aspect, the pin, or pins, respectively, in therespective cut-outs can be, or are, respectively, expanded radially, inparticular elastically and/or by separate bodies, such that the pin canbe, or is, respectively, fixed, in particular axially and/ornon-rotatably, in the cut-out. In one embodiment the pin can be, or is,fixed in the cut-out in a friction-locking manner, by means of theradial expansion. Additionally or alternatively, the pin can be, or is,fixed in the cut-out in a form-locking manner by the radial expansion. Asterile barrier can be disposed, in particular, between the pin and thecut-out, in particular, it can be, or is, clamped therebetween, and isthus disposed in a simple and compact manner between the drive unit andthe instrument shaft.

In one embodiment a clamping means is provided for the radial expansionof one or more of each of the pins inserted in a cut-out in themechanical interface. This clamping means can be manually ormechanically actuated in a further development, in particular by aseparate, preferably electric motor powered, clamping means drive. Itcan be actuated, in particular, mechanically, hydraulically,pneumatically and/or by electromagnetic means. By way of example, aclamping means drive can be path- or force-controlled such that, afteran insertion of a pin in the cut-out, it expands radially, in particularby means of an adjustment or actuation of the drive assembly. The pincan be designed such that it is an integrated part, or a separate part,of the output drive or input drive element, respectively, in particularas a separate and/or elastic body, which is connected to the rest of theoutput drive or input drive element such that it can be released, orcannot be released, therefrom, in particular in a material-bondedmanner, preferably by means of an adhesive.

For the elastically radial expansion, the pin, in particular its elasticbody, can be made of plastic in a further development, in particular itcan be made of polyurethane and/or silicone. For a non-elasticexpansion, the pin can have one or more separate, in particularlamellar, bodies, that can be displaced radially, in particular that canbe pivoted radially outward about an axis, or can be displaced in atranslational manner in the pins, or guided into the rest of the outputdrive or input drive elements, respectively, and by radial displacementoutward, in particular by pivoting, can radially expand the pin, as setforth in the present invention.

In one embodiment, the pin can have a through or blind internal bore,which is pressurized, for example, hydraulically or pneumatically, inorder to expand the pin radially. A stud in the clamping means can beinserted in a through hole in the pin, and have a flange on a side lyingopposite a clamping means drive, the diameter of which is greater thanthe through hole. By tensioning the flange against the hole by means ofthe clamping means drive, the pin can be axially compressed between theflange and the clamping means drive, such that the pin expands radially.Likewise, the stud can have a contour that expands radially in the axialdirection, in particular a conical contour, such that an axialdisplacement of the stud in the pin expands the pin radially, inparticular in an elastic manner, or radially outward by the displacementof separate bodies.

According to another aspect, a wavelike gap is formed in a radialdirection between the cut-out and the pin inserted therein in which anintermediate element assembly, having one or more intermediate elements,is disposed, which can be—in particular by means of a cage permanentlyconnected to the drive unit or the instrument shaft—displaced radially,and are guided such that they are axially fixed in place. If the pin(the cut-out) is then displaced axially, its (their) wavelike outer(inner) wall facing the cut-out (the pin) is displaced in acorresponding manner. This adjusts the corresponding intermediateelement in the radial direction in a form-locking manner, which causes,on its part, a corresponding axial displacement of the cut-out (the pin)in a form-locking manner. In this manner, an axial displacement, inparticular, of the pin, or the cut-out, respectively, can betransferred, in a positively driven manner, to the cut-out, or the pin,respectively, such that it is form-locking. A sterile barrier can bedisposed, in turn, in particular between the pin and the cut-out, inparticular between the pin and the intermediate element assembly, orbetween the intermediate element assembly and the cut-out, in particularsuch that it is, or will be, clamped therein, and thus, be disposed in asimple and compact manner between the drive unit and the instrumentshaft.

According to one aspect, the mechanical interface, in each case, has atilt lever for coupling one or more pairs of output drive and inputdrive elements. In the present case, a tilt lever is understood to be,in the typical manner, in particular, a lever, which is rotatablysupported at one location, in particular on an end, and at a locationaxially spaced apart therefrom, in particular at an opposite end, ispositively driven in a form-locking manner by a rotatable ordisplaceable connecting member. A sterile barrier can be disposed, inparticular, between the tilt lever and the connecting member, inparticular, it is, or can be, clamped therebetween, and thus disposed ina simple and compact manner between the drive unit and the instrumentshaft. In particular, an output drive element can be designed as thetilt lever, and an input drive element allocated thereto can be designedas the connecting member. Likewise, an input drive element can bedesigned as the tilt lever, and an output drive element allocatedthereto can be designed as the connecting member.

In an embodiment of one of the aforementioned aspects, one or moreoutput drive elements of the output drive assembly can be guided oractuated such that it can be adjusted in a translational manner. By wayof example, an output drive element can form an output drive axle of alinear motor, or can be coupled to such. Additionally, or alternatively,one or more input drive elements of the drive assembly can be guided oractuated such that it can be adjusted in a translational manner. By wayof example, an input drive element can form, or be coupled to, a rod,which is connected in an articulated manner to an end effector.Likewise, an input drive element can also, by way of example, beconnected to a pull cable for actuating a degree of freedom of aninstrument.

Likewise, one or more output drive elements of the output drive assemblycan be guided or actuated such that it can be adjusted in a rotationalmanner. By way of example, an output drive element can form, or becoupled to, an output drive axle of a rotation motor. Additionally, oralternatively, one or more input drive elements of the drive assemblycan be guided, or actuatable, such that it can be rotationally adjusted.By way of example, an input drive element can be a shaft, on which apull cable is wound for actuating a degree of freedom of an instrument.

In an embodiment of one of the aforementioned aspects, one or moreoutput drive elements are coupled to a coupling means such that atranslational movement by the coupling means is converted to arotational movement by the element. Likewise, one or more output driveelements can be coupled to a coupling means such that a rotationalmovement by the coupling means is converted to a translational movementby the element.

Additionally or alternatively, one or more input drive elements can becoupled with a (further) coupling means, such that a translationalmovement by the element is converted to a rotational movement by thecoupling means. Likewise, one or more input drive elements can becoupled with a (further) coupling means, such that a rotational movementby the element is converted to a translational movement by the couplingmeans.

In a further development a coupling means can have a rotating-thrustbearing, in particular a pivot joint that can be displaced in theconnecting member in a translational manner. Additionally oralternatively, a coupling means can have a rotatably mounted lever or arotatably mounted rocker, or a lever with a pivot bearing point, whichis disposed between two pickups, such as further pivot bearing points,cable attachments or suchlike, for example. In particular, a rotationalmovement of the coupling means can be mechanically converted to atranslational movement of an output drive or input drive element in thismanner. Additionally or alternatively, a coupling means can have gearteeth, in particular two sets of gear teeth that engage in one another,or mesh with one another, respectively, of which, in a furtherdevelopment, one is moveably mounted in a rotational manner, and theother is likewise mounted in a rotational manner, in particular as acombing spur gear, or in a translational manner, in particular as a wormgear, or a pinion gear.

In an embodiment of one of the aforementioned aspects, the instrumentshaft has a flange, wherein the mechanical interface is disposed on asurface of this flange facing an end effector. In a further developmentthe drive unit has a corresponding cut-out through which the instrumentshaft is inserted, which in the present case is also referred to as aback-loading assembly. Likewise, the mechanical interface can bedisposed on a surface of this flange facing away from the end effector,such that drive unit can likewise be disposed on a surface of theinstrument shaft facing away from the end effector, which in the presentcase is also referred to as a front-loading assembly. In an alternativedesign, the mechanical interface can be disposed on a lateral surface ofthe flange on the instrument shaft, which in the present case is alsoreferred to as a side-loading assembly.

In particular when the mechanical interface has a one-sided linkage, oneor more output drive elements and/or one or more input drive elementscan be pre-tensioned counter to their respective adjustment directionsin an embodiment, in particular by means of a spring. In this manner,also with a one-sided linkage, an element of the other drive element canalso be displaced counter to the linkage direction by means of thespring. Also with two-sided linkages, such as a radially expanded pin,an intermediate element assembly, or a tilt lever, for example, apre-tensioning of an output drive or input drive element counter to itsadjustment direction can advantageously reduce play.

Likewise, when a one-sided linkage is formed between an output driveelement and an input drive element allocated thereto, in particular, afurther output drive element and an input drive element allocatedthereto can be provided, the one-sided linkage of which is in theopposite direction of a one-sided linkage to the one output drive andinput drive element. In other words, for actuation in opposingdirections, or actuation of a degree of freedom in two oppositedirections, respectively, a pair of output drive or input drive elementsacting in opposite directions can be provided in each case. This isunderstood in the present case to mean, in particular, that an actuationof an output drive element in a pair actuates, or adjusts, respectively,the other output drive element of this pair, in particular in apositively driven manner, in the opposite direction. Also with two-sidedlinkages, such as a radially expanded pin, an intermediate elementassembly, or a tilt lever, for example, a further output drive and inputdrive element acting in the opposite direction can be provided, in orderto advantageously present a redundant and precise actuation of thedegree of freedom.

In particular, when there is a static over-determination as a result ofa pair of output drive or input drive elements acting in opposingdirections, a compensation means can be provided in an embodiment of thepresent invention, in order to compensate for tolerances. A tolerancecompensation means of this type can exhibit, in particular, an elasticresiliency in an output drive or input drive element, in particular inits adjustment direction. Additionally or alternatively, a couplingmeans coupled to an output drive or input drive element can also exhibitan elastic resiliency in the adjustment direction of the element.Additionally or alternatively, a sterile barrier, disposed between theoutput drive and input drive element, can also exhibit an elasticresiliency. An elastic resiliency can be defined or formed, inparticular, by an elastic material, which displays macroscopicdeformations in normal operation, and/or by a corresponding shaping orflexible composition, respectively, in particular a local materialweakening, preferably a constriction thereof. Likewise, a compensationmeans can also have a bearing or bearing axle, respectively, inparticular pre-tensioned, that can be displaced in an adjustmentdirection, in particular for a coupling means coupled to an output driveor input drive element. Even without a static over-determination, atolerance compensation of this type can be advantageous, in order tocompensate for assembly or manufacturing tolerances, for example, in akinematic chain.

In an embodiment of one of the aforementioned aspects, a front surfaceof an output drive element and/or a front surface of an input driveelement can be flat, in particular in order to present, advantageously,a larger contact surface. Likewise, a front surface of an output driveelement and/or a front surface of an input drive element can be convex,in particular in order to present, advantageously, a well-definedcontact region. Additionally or alternatively, a front surface of anoutput drive or input drive element can have at least one projection,and a front surface, facing this element, of an input drive or outputdrive element that can be, or is, coupled thereto can have acorresponding cut-out, in which this projection engages.

A further aspect of the present invention relates to the sterility ofthe instrument. For this, according to one aspect, which can be combinedwith one or more of the preceding aspects or embodiments, the instrumentassembly, or the instrument, respectively, has a sterile barrier, whichis provided in order to encase the drive unit, in particular in anairtight manner, and is to be disposed between the drive unit and theinstrument shaft, or, respectively, which encases the drive unit in asterile manner, and is disposed between the drive unit and theinstrument shaft. The sterile barrier can be designed in the manner of afoil and/or as a single use, or disposable, article in a furtherdevelopment.

According to one aspect, the sterile barrier has a cuff in the region ofthe mechanical interface, in an adjustment direction of the output driveand input drive assembly. The cuff can be formed by a sleeve in oneembodiment, which extends in an axial adjustment direction, which rollsup or rolls out, or is inverted when the output drive or input driveelement is adjusted axially. In general, the cuff is understood, inparticular, to be a excess material of the sterile barrier, in order tocompensate for, or to accompany, respectively, in particulartranslational, actuations of the output drive or input drive elements,which is stored in a folded or rolled-up manner during one adjustmentstate, and is unfolded or unrolled in another adjustment state.

In one embodiment, the cuff can be designed such that it ispre-tensioned. In this case, this means that the cuff becomeselastically deformed counter to the pre-tensioning during an adjustmentmovement, or actuation, respectively, of the output drive or input driveelement, and with a movement in the opposite direction, returns to thepre-tensioned state. In this regard, in the present case, for a moreconcise explanation, an excess of material, in particular, which isprovided to compensate for an actuation of an output drive or inputdrive element, is referred to in general as the cuff, which can eitherbe pre-tensioned or without tension, or loose, respectively. In afurther development, the cuff has a bellows, the pleating of whichinduces a pre-tensioning in a fundamental configuration. The pleating,or the bellows, respectively, can extend in one embodiment in anadjustment direction and/or transverse thereto, by means of whichcorresponding fundamental configurations and deformations can bedepicted.

According to one aspect, the sterile barrier has at least one seal inthe region of the mechanical interface that can be displaced withoutcontact in a translational manner. This can be designed, in particular,in the manner of a gap seal or a labyrinth seal, and is preferablytelescopic, i.e. it comprises two or more components that can be axiallydisplaced relative to one another, and which form a seal, in particularraces, preferably concentric races. Advantageously, actuations withweaker dissipation can be depicted by means of such contact-freetranslational seals. In a further development, in a contact-freetranslational seal, a transference of forces is dissipated via thesterile barrier instead of being conveyed thereby.

As has already been explained above, the sterile barrier can have acompensation means to compensate for tolerances, in particular anelastic resiliency. In a further development this can, in particular,exhibit a local thickening of the walls for this purpose, in a contactregion of an output drive and/or input drive element, in particular aone-sided linkage, in order to make available a more elastic path. In afurther development the elastic resiliency, in particular a localthickening of the walls, can exhibit a greater stiffness than asurrounding region of the sterile barrier, in order to improve thetransference behavior. For this, the sterile barrier can have a localmaterial modification in an embodiment of the present invention in acontact region of an input drive and/or output drive element, inparticular, locally, a material having a greater or lesser stiffnessthan in a surrounding area of the contact region.

According to one aspect, the sterile barrier has at least one elementextension in the region of the mechanical interface. This is can be, oris, respectively, attached in a releasable manner to an output drivebase in one embodiment, which penetrates the sterile barrier in adestructive manner, and forms, together with the element extension, anoutput drive element. Likewise, an element extension can be, or is,respectively, releasably attached to an input drive element base, whichpenetrates the sterile barrier in a destructive manner, and, togetherwith the element extension, forms an input drive element. By way ofexample, a sterile, in particular a sterilized, input drive element baseof the drive assembly for the sterile instrument shaft can penetrate thesterile barrier in a destructive manner, and be connected to the elementextension on the side facing away from the instrument shaft, which isthen coupled inside the sterile barrier, or sterile casing,respectively, to the output drive element allocated thereto. Likewise, asterile element extension can be disposed on the sterile barrier on theinstrument shaft side, such that it makes contact in a sterile manner,before an output drive element base penetrates the sterile barrier in adestructive manner, and is connected to the element extension on theside facing the instrument shaft. In this manner, the sterility, in eachcase, of the instrument shaft can be ensured when coupled to a driveunit that is not sterile, which is encased by the sterile barrier.

A further aspect of the present invention relates to the attachment of adrive unit and an instrument shaft to one another. For this, accordingto one aspect, which can be combined with one or more of the precedingaspects or embodiments, respectively, the instrument assembly, or theinstrument, respectively, has an attachment element for establishing areleasable connection to the drive unit, which is provided such that iscan be disposed, preferably exclusively from the outside, on one of thesurfaces of the sterile barrier facing away from the drive unit, orwhich is disposed exclusively on a surface of the sterile barrier facingaway from the drive unit. The attachment element can be connected to theinstrument shaft in a releasable manner, in particular in a form-lockingor friction-locking manner, or it can be connected in a non-releasablemanner, such that it is clipped thereto, or is an integral part thereof.The sterile barrier is closed in one embodiment, at least in the contactregion with the attachment element, preferably in the region of theentire mechanical interface; in particular, it can be clamped betweenlocking projections and/or cut-outs by the drive unit and the attachmentelement without damage thereto, or without forming holes therein. Inthis manner, no sealing is necessary when attaching the instrument shaftto the encased drive unit. In a further development, the attachmentelement is designed accordingly without seals.

The attachment element can, in particular, be designed separately as asterile disposable article, or an adapter that can be sterilized, andcan be, or is, respectively, attached to the drive unit in afriction-locking and/or form-locking manner, in particular by means of aclip connection. In particular in combination with a one-sided linkage,the attachment and coupling functionalities can thus be separated, anddivided between the attachment element and the interface.

According to one aspect of the present invention, a surgical instrumenthas an instrument shaft, on which an end effector is disposed, and adrive module having a drive for actuating one or more degrees of freedomof the end effector in relation to the instrument shaft. The instrumentshaft and drive module can be, or are, respectively, connected, inparticular in a releasable manner, to one another in one embodiment. Ina further development, a sterile barrier is disposed between theinstrument shaft and the drive module, in particular in order to shielda drive that is more poorly sterilizable, or not sterilizable, against asurgical environment. The surgical instrument is a minimally invasivesurgical instrument in one embodiment, the instrument shaft of which isprovided, or designed, for the partial insertion in a patient, inparticular by means of a trocar and/or a local access point, thecircumference of which, in one embodiment, corresponds at most to twicethe outer circumference of the instrument shaft part that is to beinserted.

The instrument can, in particular, be a manipulator-guided instrument.For this, the instrument shaft and/or the drive module has, in oneembodiment, a mechanical and/or signal-based interface for the couplingthereof to a manipulator. Accordingly, according to one aspect of thepresent invention, a manipulator assembly having one or moremanipulators, in particular robots having six or multiple axes, whichguide an inventive surgical instrument, is placed under protection.

The end effector has one, two or more translational degrees of freedom,and/or one, two or more rotational degrees of freedom with respect to,or in relation to, the instrument shaft. In one embodiment, thesingle-piece end effector has a translational or rotational degree offreedom, and is designed, by way of example, as an extendable needle ora rotatable scalpel blade. In another embodiment, the two-piece endeffector has two rotational degrees of freedom, and is designed, by wayof example, as a scissors, a clamp, or suchlike. Likewise, the endeffector can, in particular, have an optics system for transmittingand/or receiving electromagnetic radiation, in particular a laseremission or endoscope lens, and/or an opening for suctioning off and/orremoving gas and/or fluids, which can be rotated about one or more axesof degrees of freedom and/or can be retracted or extended.

The drive has one or more motors in one embodiment, in particularelectric motors, for actuating the degree(s) of freedom of the endeffector. Additionally or alternatively, the drive can also haveelectromagnetic, hydraulic and/or pneumatic actuators.

In order to actuate an end effector, in particular by means of a drive,a drive train assembly is provided according to one aspect of thepresent invention. This can be disposed in one embodiment as aninstrument shaft-side drive train assembly on, in particular in, aninstrument shaft of an, in particular, minimally invasive and/ormanipulator-guided, surgical instrument. Additionally or alternatively,an inventive drive train assembly can be disposed as a drive module-sidedrive train assembly on, in particular in, a drive module of an, inparticular, minimally invasive and/or manipulator-guided, surgicalinstrument. Accordingly, according to one aspect of the presentinvention, an instrument shaft and a drive module having an inventivedrive train assembly are placed under protection.

A drive train assembly according to one aspect of the present inventionhas one or more drive trains for actuating one or more degrees offreedom of an end effector of a surgical instrument in relation to aninstrument shaft by means of a drive.

A drive train can, in one embodiment, at least substantially, transferonly tractive forces, or, respectively, be designed as a flexible drivetrain, in particular as a pull cord, or cable, respectively. In anotherembodiment, a drive train can transfer pressure forces, in particular,at least substantially, only pressure forces or both tractive andpressure forces, in particular as a push bar or rod, or as a tappet.Likewise, a drive train can also, in one embodiment, at leastsubstantially, transfer only torques and/or exhibit a gear ratio and/ora gearing. In one embodiment, a drive train is designed as a solid shaftor a hollow shaft, or as a solid rod or a hollow rod. In general, adrive train, as set forth in the present invention, transfers forcesand/or movements, in particular mechanically, between the drive and theend effector, in particular in order to actuate these in a degree offreedom in relation to the instrument shaft.

According to one aspect of the present invention, a metering assembly isdisposed on the drive train assembly for registering a load to one ormore, in particular all, of the drive trains.

As a result, one or more so-called active, or generalized loads that acton the degree(s) of freedom of the end effector can be registered,preferably directly. A generalized or minimal force is understood tomean, in the present case, in particular in the normal manner, a loadthat, in the case of a, potentially virtual, movement in the degree offreedom provides physical, or potentially virtual, work. By way ofexample, the generalized force in a rotational degree of freedom is atorque about the axis of the rotational degree of freedom. Accordingly,a load as set forth in the present invention can, in particular,comprise, in particular be, a force, an anti-parallel pair of forces, ora torque, respectively, a tension, in particular a tractive, pressure,and/or bending tension, and/or an, in particular elastic, deformationresulting from such forces, torques, or tensions, respectively, inparticular an elongation or compression.

This in turn can be explained in an illustrative manner, using FIG. 34as an example: the clamping force F_(E1) causes a torque about the pivotbearing axis of the blade 2.1 having the rotational degree of freedomq₁. This in turn results in corresponding loads F_(S1), F_(S2) in theinstrument shaft-side drive trains 21, 22, and this in turn results inloads F₁, F₂ in the drive module-side drive trains 21, 22. One can seethat the active, or generalized, loads are registered directly by ametering assembly on the drive trains 21, 22 and/or on the drive trains11, 12, which act on the degrees of freedom of the end effector, andthus, in particular, can transmit an advantageous feedback from theoperating field to the teleoperator. As a matter of course, in oneembodiment, the surgical instrument can additionally have a meteringassembly for registering a load in the instrument shaft, in particularbetween the instrument shaft and the end effector (bearing), and/orbetween the instrument shaft and the drive module, in order to registerso-called passive loads as well, in addition to the active loads, inparticular support or bearing loads. If, for example, the clamp in FIG.34, in the depicted constellation, pushes its tips vertically downward,then pure bearing loads result in the pivot joints of the blades 2.1,2.2 thereby, which are registered via such an additional meteringassembly for registering a load in the instrument shaft 20, and theseloads are further processed; in particular they can be transmitted tothe teleoperator.

In one embodiment, there may be a further advantage in that the meteringassembly for registering at least one load in the drive train assemblyis disposed on the drive train assembly, and thus preferably in theinterior of the instrument shaft, or on, in particular in, a drivemodule, and thus an advantageous, in particular a protected, meteringlocation and/or a metering location that is removed from the operatingfield, or the end effector, in particular an extracorporeal meteringlocation and/or a metering location in the proximity of the drive, canbe made available.

In one embodiment of the present invention, the drive train assembly hastwo or more drive trains, in particular in opposing directions, foractuating the same degrees of freedom of the end effector. This isillustrated in an exemplary manner in FIG. 34: there, the blade 2.1 isactuated in its degree of freedom q₁ by the drive trains 21, 22 actingin opposing directions, these being, for example, two pull cables orpush rods, which in turn are actuated in a translational manner by thedrive trains 11, 12 acting in opposing directions, these being tappets,for example, which are actuated in opposing directions by an electricmotor 13.

In one embodiment example, the metering assembly has at least onemetering means, which is disposed on one of the drive trains forregistering a load in this drive train. In a further development, themetering assembly has a first metering means, which is disposed in afirst drive train for registering a load in this drive train, and asecond metering means, which is disposed in a second drive train, inparticular a drive train acting in the opposite direction, forregistering a load in this drive train, wherein the same degree offreedom of the end effector can be actuated by the first and the seconddrive train.

In one embodiment, the drive train assembly has a first drive train foractuating a first degree of freedom of the end effector, and anotherfirst drive train for actuating another degree of freedom of the endeffector. In a further development, the drive train assembly can have asecond drive train for actuating the first degree of freedom of the endeffector and/or another second drive train for actuating the otherdegree of freedom of the end effector. As a matter of course, the endeffector can have further degrees of freedom and corresponding firstand, potentially, second drive trains.

In a further development, the metering assembly has a first meteringmeans, which is disposed on the first drive train for actuating thefirst degree of freedom of the end effector, for registering a load inthis drive train. Additionally or alternatively, the metering assemblyhas a second metering means, which is disposed on the second drive trainfor actuating the first degree of freedom of the end effector, inparticular acting in the opposite direction, for registering a load inthis drive train. Additionally or alternatively, the metering assemblyhas another first metering means, which is disposed on the other firstdrive train for actuating the other degree of freedom of the endeffector, for registering a load in this drive train. Additionally oralternatively, the metering assembly has another second metering means,which is disposed on the other second drive train for actuating theother degree of freedom of the end effector, in particular acting in theopposite direction, for registering a load in this drive train.

In one embodiment there are two or more metering means, which aredisposed on two drive trains for actuating the same degrees of freedomof the end effector, in particular in opposing directions, coupledtogether by signal-based technology. They can be connected to oneanother in particular by means of electric lines, or, in particular in acontrol means, they are, or can be, linked by means of a computer, inparticular in an additive or subtractive manner.

As a result, in one embodiment, in particular a shared load, inparticular a pre-tensioning, can be compensated for by means of signals,at least substantially, in two drive trains for actuating the samedegree of freedom, and thus, preferably, the resulting active, orgeneralized, load can be determined in a direct manner. In general, inone embodiment a first and a second metering means, which are disposedon two drive trains for actuating the same degree of freedom of the endeffector, in particular in opposing directions, are linked to oneanother in a compensatory manner. A compensatory linking is understoodto mean a linking of the signals from the first and second meteringmeans, such that a predefined load, in particular a load in a predefineddirection, is compensated for at least substantially, or, respectively,the common, linked signal of the first and second metering means, atleast substantially, is independent of the load, which is registered byboth the first as well as the second metering means.

In particular for this, the first and second metering means, which aredisposed on a first or second drive train for actuating the same degreeof freedom, can be linked to one another in two branches of a Wheatstonebridge circuit, in particular in two branches of a Wheatstonehalf-bridge circuit, which preferably lie in a series between a bridgeinput or supply voltage. In a further development, the metering assemblycan have a third metering means, which, in particular, is disposedopposite the first metering means on the first drive train forregistering a load in this drive train, and a fourth metering means,which is disposed, in particular, opposite the second metering means, onthe second drive train for registering a load in this drive train,wherein the first metering means in a first branch, the second meteringmeans in a second branch, in particular interposed in a bridge input orsupply voltage in a series with the first metering means, the thirdmetering means in a third branch, interposed in the supply or excitationvoltage, in particular in parallel to the second metering means, and thefourth metering means in a fourth branch, interposed in the supplyvoltage, in particular in parallel to the first metering means, arelinked to one another in an electric circuit, in particular a Wheatstonefull-bridge circuit. As a result, in one embodiment, not only sharedloads, but also different types of loads, in particular bending loads,in the same drive train can already be compensated for, at leastsubstantially, by means of signal-based technology. Additionally oralternatively, loads that have been registered can be amplified in termsof their signals, in particular in that load components corresponding toone another, which are registered by different metering means, arecombined through the linking.

One metering means of the metering assembly can, in one embodiment, haveone or more strain meters for registering a mechanical load, inparticular by electrical, magnetic, optical and/or acoustic means. Thesemeters can, in particular, be, preferably foil-type, strain meterstrips, the resistances of which preferably change with their elasticelongation, semi-conductor strain meters, optical, preferably fibertype, strain meters, in particular strain meters based on Bragg orFabry-Perot technology, such as FBG strain meters (“Fiber BraggGrating”), acoustic strain meters, such as, in particular, so-called SAWstrain meters (“Surface Acoustic Wave”), piezoelectric or magnetoelasticsignal transmitters, or suchlike.

In one embodiment, one or more metering means of the metering assemblyare disposed on a drive train for registering, at least substantially,an axial tractive and/or pressure load in this drive train. By way ofexample, a strain meter strip can be, at least substantially, disposed,or oriented, respectively, in the longitudinal direction on a pull cableor push rod.

In one embodiment, one or more metering means of the metering assemblyare disposed, at least substantially, in a cut-out in a drive train. Asa result, the metering assembly can be protected in one embodiment.Additionally or alternatively, a protrusion of the metering assemblyover the outer edge of the drive train(s) can be reduced, in particularit can be prevented, which can facilitate the manipulation, inparticular the operation and/or assembly, thereof.

Additionally or alternatively, the wall thickness of the drive train canbe reduced in the region of one or more metering means, in particular bythe cut-out described above. As a result, the sensitivity of themetering assembly can be increased in one embodiment. In one embodiment,in order to reduce the thickness of the wall, the drive train can have ahollow chamber in the region of one or more metering means, inparticular an expansion of a hollow chamber. In a further development,the drive train can have a, preferably thin-walled, sleeve, which hasone or more metering means of the metering assembly disposed on theouter and/or inner surface thereof. The sleeve can be connected to thedrive train with other components, in particular rods or shafts having asolid cross-section, in a material bonded manner, in particular by meansof welding or adhesive.

In one embodiment, an inventive drive train assembly is disposed on, inparticular in, a drive module of a surgical instrument, to which aninstrument shaft, which has an end effector, can be connected, inparticular in a releasable manner. The drive module-side drive trainassembly can have, in particular, a mechanical interface for thecoupling of an instrument shaft-side drive train assembly, for actuatingan end effector, thereto. A drive module-side drive train can have, inparticular, a shaft of an electric motor of the drive, or be coupled tothis shaft, in particular in an articulated manner. Loads that arespaced far apart from the end effector, in particular extracorporealloads, preferably behind a sterile barrier, or in a sterile housing ofthe drive module, respectively, can be registered in an advantageousmanner by means of a drive module-side metering assembly.

Additionally or alternatively, an inventive drive train assembly can bedisposed in one embodiment on, in particular in, an instrument shaft ofa surgical instrument having an end effector, with which a drive module,which has a drive, can be connected, in particular in a releasablemanner. The instrument shaft-side drive train assembly can have, inparticular, a mechanical interface, for coupling a drive module-sidedrive train assembly thereto, which is coupled to the drive. Preferably,loads in the proximity of the end effector can be registered directly bymeans of an instrument shaft-side metering assembly.

A drive module-side drive train assembly and an instrument shaft-sidedrive train assembly, on at least one of which a metering assembly isdisposed for registering loads in this drive train, are coupled, orreleasably coupled, respectively, to one another in one embodiment ofthe present invention.

They can be coupled, or are coupled, respectively, to one another, inone embodiment, in a translational manner. In the present case, inparticular, this is understood to mean that a drive module-side drivetrain, and an instrument shaft-side drive train coupled thereto, aremoveable, or are moved, respectively, in a translational manner on theinterface, in order to actuate a degree of freedom of the end effector,wherein this translational movement is, or can be, converted to arotational movement in other drive module-side and/or instrumentshaft-side drive trains. Likewise, a drive module-side drive train, andan instrument shaft-side drive train coupled thereto, can be, or are,coupled to one another in a rotational manner on the interface, whereinthis rotational movement in the interface is, or can be, converted to atranslational movement in other drive module-side drive train and/orinstrument shaft-side drive train.

In one embodiment, a drive module-side drive train assembly and aninstrument shaft-side drive module assembly, on at least one of which ametering assembly is disposed for registering loads in this drive train,can be coupled, or are releasably coupled, respectively, in a one-sidedmanner via an interface. In the present case, this is understood to meanthat a drive module-side drive train, and an instrument shaft-side drivetrain coupled, or that can be coupled, thereto, have a so-calledone-sided linkage, or, respectively, that only forces or torques in onedirection can be transferred, in particular, only pressure forces. In afurther development, a drive module-side drive train and an instrumentshaft-side drive train that is, or can be, coupled thereto, have tappetslying opposite one another, preferably flush, on the interface, whichare mounted such that they can be displaced, and only transfer, at leastsubstantially, pressure forces to one another.

In one embodiment, a drive module-side drive train assembly, and aninstrument shaft-side drive train assembly that is, or can be, coupledthereto, are coupled via a, preferably foil-type and/or flexible,sterile barrier. The sterile barrier can, in one embodiment, accompanytranslational movements of the drive train assembly on the interfacewith, preferably elastic, deformation thereof, and/or have moveable, inparticular displaceably and/or rotatably mounted coupling elements.

As explained above, in one embodiment, preferably an active orgeneralized load can be directly registered by means of an inventivemetering assembly, and thus improve a feedback to a teleoperator.Accordingly, according to one aspect of the present invention, a manualteleoperation means for a surgical instrument is controlled on the basisof one or more loads registered by the measurement assembly, wherein,for a more compact depiction, a regulating is also referred to ingeneral as controlling as set forth in the present invention. A manualteleoperation means can have, in particular, one or more levers,handles, gloves, joysticks, or a so-called mirroring-instrument, themovements of which are coupled, preferably in a control manner, to themovements of the surgical instrument. Based on the loads registered bythe metering assembly, a teleoperation means of this type can beactuated, in particular by means of a motor, in order to transmit ahaptic feedback pertaining to the surgical process to the teleoperator.In particular, forces acting on the end effector can be exerted on theteleoperation means on the basis of loads that have been registered bythe metering assembly, in order to transmit a force-feedback to theteleoperator.

Additionally or alternatively, loads registered by the metering assemblycan also be used to control, in particular to regulate, the drive. Byway of example, a target force that is to be exerted by a motor can becompared with an actual force in a drive train, and the motor can beregulated based on this comparison.

Accordingly, according to one aspect of the present invention, a controlmeans for controlling a surgical instrument is configured to furtherprocess one or more loads registered by the metering assembly, inparticular to control the drive and/or a manual teleoperation means onthe basis of loads registered by the metering assembly. A means as setforth in the present invention can be designed in the manner of hardwareand/or software, in particular it can have a central processing unit(CPU), in particular a microprocessor, preferably connected to a memoryand/or bus system for transferring signals or data, in particular in adigital manner, and/or it can have one or more programs or programmodules. The CPU can be configured to process commands, which areimplemented in the form of a program stored in a memory system, todetect input signals from a data bus, and/or to transmit output signalsto a data bus. A memory system can have one or more, in particulardifferent, storage media, in particular optical, magnetic, solid stateand/or other nonvolatile media. The program can be created such that itembodies the method described herein, or is capable of executing saidmethod, such that the CPU can execute the steps of such a method, andcan thus control the drive and/or the teleoperation means.

According to one aspect of the present invention, a surgical instrumenthas an instrument shaft and a drive unit that can be connected, inparticular is connected, thereto in a releasable manner. The instrumentis a robot-guided instrument in one embodiment. For this, in a furtherdevelopment, the instrument shaft and/or the drive unit have/has aninterface, in particular a mechanical, signal and/or energy based, inparticular electric, hydraulic and/or pneumatic, interface, for theattachment thereof to a robot. In one embodiment, the instrument is aminimally invasive surgical instrument, the instrument shaft of which isprovided for partial insertion in a patient through a local, natural orartificial, hole, in particular through a body orifice, or through atrocar.

An instrument shaft according to one embodiment of the present inventionhas one or more degrees of freedom. In one embodiment, the instrumentshaft exhibits a tube, in particular an at least substantiallycylindrical tube. A degree of freedom of the instrument shaft can then,in particular, be an articulation degree of freedom for a joint betweentwo tube sections, or an elastic degree of freedom for a flexible tube.In one embodiment, the instrument shaft has an end effector, inparticular a forceps, clamp or clips, a scalpel, a drill, a needle orcannula for removing and/or introducing gases and/or fluids, and/or anoptics system for transmitting and/or receiving electromagneticradiation, in particular a fiber optics end of an endoscope or a laser.A degree of freedom of the instrument shaft can then be, in particular,a degree of freedom of the end effector, in particular a translationalor rotational degree of freedom with respect to the tube, or afunctional degree of freedom, in particular for opening or closing aforceps, clamp, clip, cannula and/or optics system, or suchlike. Afunctional degree of freedom as set forth in the present invention can,in particular, describe a movement possibility for two parts of an endeffector in relation to one another. In one embodiment, the tube canhave a rotational degree of freedom with respect to a proximalinstrument housing of the instrument shaft.

In order to actuate a degree of freedom, the instrument shaft has one ormore input drive links, in particular acting in opposing directions. Aninput drive link, in one embodiment, is mounted in an interface of theinstrument shaft such that it is translational, or can be displaced,respectively, and/or is rotational, or can be rotated, respectively, inorder to actuate a translational or rotational movement of a degree offreedom of the instrument shaft. For this purpose, it can be coupled toa tube (part) or end effector of the instrument shaft, in particular bya push rod, a pull cable or cable drum, and/or a gearing, in particularfor converting translational and rotational movements into one another.In one embodiment, the instrument shaft, in particular an interface ofthe instrument shaft for coupling with the drive unit, has an inputdrive link assembly with numerous input drive links. In a furtherdevelopment, at least one degree of freedom of the instrument shaft canbe actuated in opposing directions by two input drive links, inparticular acting in opposing directions, for example a pivotable endeffector can be pivoted up and down by means of two push rods running inopposite directions.

A drive unit according to one embodiment of the present invention has ahousing and one or more drive modules. At least one drive module,preferably all drive modules, exhibits, in each case, a drive and anoutput drive link assembly having one or more moveable output drivelinks. The drive can have, in particular, an electromagnetic, hydraulic,or pneumatic rotational or linear motor, in particular, it can be anelectric motor.

In one embodiment, the drive actuates exactly one output drive link. Inanother embodiment, the drive actuates two output drive links, inparticular in opposing directions. One or more output drive links aremounted in one embodiment in an interface of the drive module, such thatthey are translational, or can be displaced, respectively, and/orrotational, or can be rotated, respectively, in order to actuate adegree of freedom of the instrument shaft by means of a translational orrotational movement. The output drive link and input drive linkassemblies can be, or are, directly, or via a coupling, coupled in aone-sided manner in one embodiment. This is understood to mean, in thenormal sense, that forces can only be transferred in one actuationdirection from the output drive link to the input drive link, while theoutput drive link and the input drive link can distance themselves fromone another in opposite directions. In a further development, one outputdrive link assembly has two output drive links that are actuated inopposing directions, in particular two push rods, which can be, or arecoupled, directly or by means of a coupling, at one end to correspondinginput drive links running in opposite directions. In another embodiment,the output drive link assembly and the input drive link assembly can be,or are, coupled directly or via a coupling, in a two-sided manner. Thisis understood to mean, accordingly, that forces in two opposingactuation directions can be transferred from the output drive link tothe input drive link. In a further development, one output drive linkassembly has a rotatable output drive link, in particular an outputdrive shaft of an electric motor or gearing, which can be, or is,non-rotatably coupled to a corresponding rotatable input drive link. Fora more compact depiction, in the present case an anti-parallel pair offorces, i.e. a torque, is also referred to in general as a force.

According to one aspect of the present invention, one or more drivemodules in the, in particular closed, housing of the drive unit are eachmoveably mounted and pre-tensioned in a coupling direction, or againstthe input drive link assembly. The coupling directions of two,preferably all, drive modules can be, at least substantially, parallel.Likewise, the coupling directions of two drive modules can form anangle, which is preferably less than 90 degrees, and in particular isless than 45 degrees.

In that the individual output drive links are not pre-tensioned, or notonly the individual output drive links are pre-tensioned, as is proposedin WO 2011/143022 A1, specified in the introduction, but rather,according to this aspect, exclusively, or additionally, the drive modulein the housing, and as a result, its output drive link assembly as awhole, is pre-tensioned, the coupling between the output drive assemblyand the input drive assembly can be improved in one embodiment.

Additionally or alternatively, the weight, the installation space,and/or the expenditure can be reduced, and/or the operation thereof canbe improved.

In one embodiment, a drive module has a hydraulic, pneumatic and/orelastic tensioning means, in particular at least one hydraulic orpneumatic cylinder and/or one compression and/or tractive spring, forpre-tensioning, which restrains the drive module in the housing, and ispre-tensioned in the coupling direction, or against the input drive linkassembly, respectively. A hydraulic or pneumatic tensioning means can bedesigned such that it is switched on and off in a further development,in particular in a pressureless state, in which it, at leastsubstantially, exerts no force. Advantageously the adjustment of thedrive module in the housing, after removal of the excess pressure in ahydraulic or pneumatic tensioning means, does not require anyappreciable operating force.

Additionally or alternatively, in one embodiment, a drive module canhave a magnet assembly for pre-tensioning the drive module. The magnetassembly can have one or more permanent magnets or electromagnets, whichare disposed on either the housing or the drive module. The other,either the drive module or the housing, can have one or more additionalelectromagnets and/or magnetically hard or soft regions, in particularat least one further permanent magnet, preferably lying opposite thepermanent magnets or electromagnets, and which are magneticallyattracted or repelled by these, either permanently, or when they aresubjected to current.

In one embodiment, at least one permanent magnet or electromagnet isdisposed on the housing on a side facing away from the instrument shaft,and, preferably lying opposite this, at least one further electromagnetor a magnetically hard or soft region, in particular at least onefurther permanent magnet, is disposed on the drive module. Additionallyor alternatively, at least one permanent magnet or electromagnet can bedisposed on the housing on a side facing the instrument shaft, and,preferably lying opposite this, at least one further electromagnet or amagnetically hard or soft region, in particular at least one furtherpermanent magnet, can be disposed on the drive module. Additionally oralternatively, at least one permanent magnet or electromagnet can bedisposed on the drive module on a side facing away from the instrumentshaft, and, preferably lying opposite this, at least one furtherelectromagnet or a magnetically hard or soft region, in particular atleast one further permanent magnet, can be disposed on the housing.Additionally or alternatively, at least one permanent magnet orelectromagnet can be disposed on the drive module on a side facing theinstrument shaft, and, preferably lying opposite this, at least onefurther electromagnet or a magnetically hard or soft region, inparticular at least one further permanent magnet, can be disposed on thehousing. The drive module can be pre-tensioned in the housing againstthe input drive link assembly by means of the magnetic attraction orrepulsion occurring between them.

While the pre-tensioning force decreases as the number of adjustments tothe drive module in the housing increases with a pre-tensioning by atensioning means, for example as a result of the relaxing of amechanical spring or an increase in volume in a hydraulic or pneumaticvolume, an (electro)magnetic pre-tensioning can advantageously increasewith the increasing number of adjustments to the drive module in thehousing.

In a further development, the magnet assembly has one or moreelectromagnets that can be, selectively, in particular in a controlledmanner, subjected to current. In this manner, the pre-tensioning can beexerted selectively, in particular in a controlled manner. For thepurpose of a more compact depiction, in the present case a regulation,i.e. the specification of a control variable on the basis of aregistered actual variable, is also referred to in general as a controlthereof.

In one embodiment, the magnet assembly has one or more, preferablynon-magnetic, spacer elements, which prevent a direct contact between anelectromagnet or a permanent magnet, on either the housing for the driveunit or the drive module, and a magnetically soft or hard region, inparticular a (further) permanent magnet on the other of either thehousing of the drive unit or the drive module, in order to thus avoid amagnetic short circuit, the release of which would require excessiveforce.

During or after the coupling of the output drive assembly and the inputdrive assembly, or the drive unit and the instrument shaft,respectively, according to the aspect explained above, thepre-tensioning of the drive module must be built up.

This can result, in one embodiment, as explained above, from selectivelysubjecting one or more electromagnets in the magnet assembly to acurrent. In this manner, an operator advantageously, particularly withthe high demands in running an operating theater, need only exert asmall amount of force in order to couple the drive unit to theinstrument shaft.

Additionally or alternatively, in one embodiment, a retraction assembly,in particular a mechanical and/or magnetic retraction assembly, can beprovided for retracting the drive module against the pre-tension. Thus,in one embodiment, a magnet assembly can be selectively activated, inorder to remove the drive module from the input drive assembly when itis subjected to (further) pre-tensioning by a tensioning means. If thecurrent that the magnet assembly is subjected to is reduced, preferablyselectively, in a linear manner, for example, the tensioning meansbuilds up the pre-tensioning.

A further development is based on the idea of dividing the work range ofthe drive for the drive module into an actuating field, in which thedrive actuates the output drive link assembly for actuating a degree offreedom of the instrument shaft, and a retraction field, differingtherefrom, in which the drive actuates the retraction assembly. Bothfields can be separated from one another, in particular, by a mechanicalstop for an output drive means of the drive, wherein the output drivemeans of the drive module is displaced against the pre-tensioning whenit is not resting against the mechanical stop.

In that the drive can be adjusted beyond the actuating range, the drivemodule can thus be retracted against the pre-tensioning, preferably bymeans of a motor, by means of a corresponding control of the drive,which, as explained above, advantageously facilitates the coupling ofthe instrument shaft and the drive unit.

In an advantageous further development the drive unit has a drive modulelocking assembly for locking the retracted drive module in place. Thiscan be, in particular, designed to be mechanical, preferably form-and/or friction-locking, and/or (electro)magnetic and/or pneumatic. Inan exemplary design, a catch can be adjusted and secure the drive moduleagainst a pre-tensioning induced adjustment in the coupling direction.In this manner, the (more strongly pre-tensioned) drive module, or itsoutput drive assembly, respectively, in one embodiment, can be spacedapart from the input drive assembly, also when the drive unit andinstrument shaft will be, or are, connected to one another.

According to one aspect of the present invention, the couplingdirection, in which the drive module is moveably mounted andpre-tensioned in the housing of the drive unit, forms an angle with thelongitudinal axis of the instrument shaft, which is greater than 0degrees, in particular is greater than 45 degrees. In one embodiment,the angle is, at least substantially, 90 degrees, or the couplingdirection is, at least substantially, perpendicular, or orthogonal,respectively, to the longitudinal axis of the instrument shaft.

In that the coupling direction is not parallel to the longitudinal axisof the instrument shaft, as is the case in WO 2011/143022 A1, specifiedin the introduction, but rather, according to this aspect, forms anangle with the longitudinal axis that is not zero, in particular is aright angle, in one embodiment, the deformations of the instrument shaftadvantageously do not interfere with the pre-tensioning, or they onlyinterfere to a small extent therewith, because the force directionsthereof are not aligned with one another. In this manner, a longitudinaloscillation in the instrument shaft, in particular, can preferably bedecoupled from the pre-tensioning of the drive module, at least in part,thus improving it.

The coupling direction can, in one embodiment, at least substantially,be aligned with an actuation direction of the output drive link assemblyand/or the input drive link assembly. A coupling direction is understoodto mean, in particular, a direction of movement in which an output drivelink or an input drive link is, or will be, moveably mounted andpre-tensioned, in order to be coupled to a corresponding input drivelink or an output drive link. An actuation direction is understood tomean, in particular, a direction of movement in which an output drivelink or an input drive link can move in order to actuate a degree offreedom of the instrument shaft. If, for example, an output drive linkand an input drive link coupled thereto are designed as push rods, ortappets, coupled in a one-sided manner, the direction of thelongitudinal axis of the pair of tappets, in which the output drivetappet is pre-tensioned against the input drive tappet, represents thecoupling direction. This also represents the actuation direction inwhich the pair of tappets is moved by the drive in order to actuate adegree of freedom of the instrument shaft. If, in another example, anoutput drive link and an input drive link coupled therewith are designedas two-sided, non-rotatably, coupled shafts, the longitudinal axisdirection of the shaft pair, about which the pair of tappets is rotatedby the drive in order to actuate a degree of freedom of the instrumentshaft, represents the actuation direction. This also represents thecoupling direction in which the output drive shaft is pre-tensionedagainst the input drive shaft.

In one embodiment of the present invention, the instrument shaft has amounting element for the releasable attachment, in particular in aform-locking manner, of a drive unit thereto.

The drive unit can, in one embodiment, be attachable, or attached, orwill be releasably attached in a form-locking manner by means of abayonet coupling in the mounting element. For this, either the driveunit or the mounting element can have one or more projections, which, asthe result of a rotating of the drive unit in the mounting element,engage in corresponding cut-outs in the other of either the drive unitor the mounting element. Likewise, either the drive unit or the mountingelement can have one or more projections, which, as the result of adisplacement of the drive unit inside the mounting element, preferablyby exerting a pre-tensioning force, engage in corresponding cut-outs inthe other of either the drive unit or the mounting element, and/or arepushed into these. In one embodiment, a cut-out extends in a transversedirection, in particular perpendicular, to an insertion direction of thedrive unit in the mounting element, such that a projection can bedisplaced transverse to the insertion direction in the cut-out after theinsertion of the drive unit in the mounting element, and secures thedrive unit in a form-locking manner against removal from the mountingelement in this displaced position. Preferably this displacement occursthrough the application of the pre-tensioning force, such that thedisplacement can be reversed after the pre-tensioning force has beenreleased, in order to be able to remove the drive unit from the mountingelement.

The mounting element can have a guide in one embodiment, that is asingle-piece or multi-piece, in particular form-locking, guide forinserting the drive unit in an insertion direction. The guide can, inparticular, have one or more guide grooves and/or ribs, which aredesigned to work together with corresponding projections or cut-outs onthe drive unit. In this manner, the connecting and releasing of thedrive unit and instrument shaft can be improved.

Additionally or alternatively, the mounting element in one embodimentcan have an insertion opening for inserting the drive unit in aninsertion direction. The insertion opening can, in a furtherdevelopment, be displaceable, in particular by means of a pivotableand/or displaceable lid, in order to secure the drive unit in theinsertion direction, in particular to define the insertion direction.

Additionally or alternatively, the instrument shaft can have a driveunit locking assembly for locking the drive unit, in particular in aform- and/or friction locking manner, in the mounting element, inparticular a moveable, preferably pre-tensioned, catch, which locks inplace in the drive unit when it is placed in the mounting element.

Additionally or alternatively, the mounting element can be moveable inrelation to a longitudinal axis of the instrument shaft, in particularit can be pivotable. This enables, in one embodiment, the drive unit tobe first, at least in part, inserted into the mounting element, whichhas been moved, in particular pivoted, into a mounting position, andthen to move, in particular to pivot, the mounting element into alocking position, wherein the drive unit is preferably fixed in place ina form-locking manner when the mounting element is in the lockingposition. In this manner the access, in particular, to the mountingelement can be improved, and at the same time, an anchoring function forthe drive unit in the mounting element can be integrated therein.

In one embodiment, the insertion direction can be, at leastsubstantially, perpendicular to the longitudinal axis of the instrumentshaft. The insertion opening can then be disposed, in particular, on theside facing away from the instrument shaft, in particular in order tofacilitate a change in drive units when the instrument shaft ispartially inserted in a patient. Likewise, the insertion opening can, inone embodiment, be disposed on the side facing the instrument shaft, inparticular in order to avoid an interference between numerouscooperating surgical instruments.

In another embodiment example, the insertion direction can be, at leastsubstantially, parallel to the longitudinal axis of the instrumentshaft. The insertion opening can then in turn be disposed, inparticular, on the side facing away from the instrument shaft, inparticular in order to facilitate a change in drive units when theinstrument shaft is partially inserted in a patient.

According to one aspect of the present invention, one or more moveableinput drive links of an input drive link assembly for actuating a degreeof freedom of an instrument shaft are at least substantiallyperpendicular to a longitudinal axis of the instrument shaft extendingto a mounting element of the instrument shaft for a drive unit. In oneembodiment, an interface, or a contact plane of the input drive linkassembly is, at least substantially, parallel to the longitudinal axis.

In that the input drive links do not extend parallel to the longitudinalaxis of the instrument shaft, as is the case in WO 2011/143022 A1specified in the introduction, but rather, are perpendicular thereto, atleast substantially, according to this aspect, deformations of theinstrument shaft, in an embodiment, do not interfere, or interfere onlyslightly with the coupling of the output drive assembly and the inputdrive assembly. In this manner, a longitudinal oscillation, inparticular, in the instrument shaft can preferably be decoupledtherefrom, at least in part.

In particular in order to improve an insertion of a drive unit in amounting element of an instrument shaft, in one embodiment of thepresent invention, an input drive link assembly of the instrument shaftand/or an output drive link assembly of the drive unit can be disposedin a recess, in particular in a coupling direction. Additionally oralternatively, the drive unit can have a displacement means, inparticular a convergent and/or moveable displacement means, fordisplacing an input drive link assembly of the instrument shaft whileinserting the drive unit in the mounting element of the instrumentshaft. The moveable displacement means can have, in particular, one ormore rotatable rollers, which retract input drive links of an inputdrive link assembly that protrude further than average, and thus levelthe input drive link assembly. Additionally or alternatively, thedisplacement means can have surfaces that converge in an insertiondirection, which are chamfered or convex, in particular, for retractingthe longer than average protruding input drive links. After passing overthe roller(s) and/or convex surfaces, the input drive links extend, atleast substantially, in a uniform manner toward the mounting element ofthe instrument shaft. In a further development, a surface diverging inthe insertion direction, in particular such that it is chamfered orconvex in the opposite direction, can adjoin a surface converging in theinsertion direction, in particular a chamfered or convex surface, inorder to also retract protruding input drive links when removing thedrive unit from the mounting element.

A surgical instrument according to one aspect of the present inventionhas a drive module with one or more rotatable output drive links. In oneembodiment an output drive link is an output drive shaft of an actuatorfor the drive module, in particular an electric motor, or a gearingcoupled thereto. In one embodiment, an output drive link can rotatewithout limits, in another embodiment it can rotate a maximum of 360degrees, preferably a maximum of 215 degrees.

The surgical instrument also has an instrument shaft, which can be, inparticular is, releasably connected to the drive module. The instrumentshaft has one or more, in particular intracorporeal, degrees of freedom.

In one embodiment, the instrument shaft has a rigid, articulated orflexible tube, on the distal end of which an end effector can bedisposed, in particular a scalpel, a forceps, scissors, clamp, needle,pipette or suchlike. The end effector can have an opening for emittingor receiving electromagnetic radiation, in particular a lens for acamera or a laser, and/or for gaseous and/or liquid fluids, inparticular a suction or rinsing nozzle.

The end effector can have one or more functional degrees of freedom,such as the opening and closing of a forceps or opening. Additionally oralternatively, the end effector can have one or more kinematic degreesof freedom, such as the rotation and/or displacement of a forceps oropening. An intracorporeal degree of freedom of the instrument shaft canbe, in particular, a functional or kinematic degree of freedom of theend effector, or an articulated or elastic degree of freedom of thearticulated or flexible tube. In one embodiment, the tube has one ormore degrees of freedom about its longitudinal axis. These can beimplemented by intra- and/or extracorporeal pivotal joints. For a morecompact depiction, rotational degrees of freedom about the longitudinalaxis of the tube are also referred to as intracorporeal degrees offreedom of the instrument shaft, because they represent a rotatabilityof an intracorporeal shaft end, in particular an end effector. In orderto actuate one or more degrees of freedom of the instrument shaft bymeans of the drive module connected thereto, the instrument shaft hasone or more displaceably guided input drive links, which will be, orare, coupled to the output drive link of the drive module when the drivemodule and instrument shaft are coupled to one another. In oneembodiment, an input drive link actuates one or more degrees of freedomof the instrument shaft. Likewise, numerous input drive links canactuate the same degree of freedom. In one embodiment, an input drivelink is connected to the tube or the end effector of the instrumentshaft by one or more pulling and/or pushing means, such as pull cablesor push rods, in particular in opposing directions, wherein the pullingand/or pushing means is preferably, at least substantially, parallel toa displacement axis of the input drive link. In one embodiment, an inputdrive link is displaceably guided in a form-locking manner and/orbetween two end stops.

According to one aspect of the present invention, a rotational movementof at least one output drive link in an interface between the drivemodule and the instrument shaft is thus converted to a translational, inparticular linear, movement of an input drive link coupled to the outputdrive link.

For this, the output drive link and the input drive link can be, or are,coupled, according to one aspect, in the interface in the manner of acrossing thrust crank. According to one aspect of the present invention,the interface has a groove, in particular a straight or linear groove,and a guide element that is guided in the groove in a displaceablemanner, when the output drive link and the input drive link are coupledto one another.

In one embodiment, the groove is disposed on, in particular in, theinput drive link. In a further development, the groove can betransverse, in particular at least substantially perpendicular, to adisplacement axis of the displaceably guided input drive link, or,respectively, it can form an angle therewith that is preferably between45 degrees and 90 degrees. The guide element is disposed, preferablyeccentrically, on the rotatable output drive link. In a furtherdevelopment, the axis of rotation for the rotatable output drive link istransverse, preferably at least substantially perpendicular, to adisplacement axis of the displaceably guided input drive link and/or thegroove. In one embodiment, in particular the rotational axis can form anangle with the displacement axis and/or the groove, in each case between45 degrees and 90 degrees.

Likewise, the groove can conversely be disposed on the output drivelink, and the guide element can be disposed accordingly on the inputdrive link.

The input drive link is displaceably guided, in one embodiment, on theinstrument shaft. Additionally or alternatively, it can be displaceablyguided on the drive module connected to the instrument shaft. Inparticular, the input drive link can be displaceably guided on theinstrument shaft with greater play, in particular loosely, and can bedisplaceably guided on the drive module with less play, in particularsubstantially without play, when the drive module is connected to theinstrument shaft. As a result, the more complex, precise guidance can beshifted to the drive module, thus allowing for the instrument shaft tobe designed such that it is simpler and/or more cost-effective, inparticular such that it can be more readily sterilized and/or isdesigned as a disposable article. As soon as the instrument shaft andthe drive module are connected, the drive module assumesthe—precise—guidance of the input drive link. In one embodiment theinput drive link is secured to the instrument shaft such that it cannotbe lost, in particular in a form-locking manner.

In one embodiment, the guide element has one or more rotatably mountedroller elements, for establishing contact with the groove. As a result,in one embodiment, the friction between the guide element and the groovecan advantageously be reduced. In a further development, the guideelement has a pin, on which at least one roller element is mounted inthe form of a ball race on floating bearings, which can likewiserepresent a roller element as set forth in the present invention. For amore compact depiction, one or more concentric races, the inner(most) ofwhich is disposed on the pin, and the outer(most) of which makes contactwith the groove, and of which at least one is mounted on floatingbearings on its radial inner and/or outer surface, are also referred toin general as roller elements, even if they do not execute a rolling orshifting movement. In another embodiment, numerous roller elements aredisposed, distributed in the circumferential direction, between the pinand the ball race, in particular a ball, needle, or cylinder rollerbearing. In another embodiment, one or more roller elements, inparticular a ball, needle or cylinder roller bearing, have no outerrace, are disposed on the pin, which make contact with the groove whenthe output drive and input drive element are coupled.

In order to couple the output drive element and the input drive element,play between the groove and the guide element in the displacement axiscan be advantageous. On the other side, for the precise actuation of theinstrument shaft by the drive module, a coupling in this axis withoutplay, to the greatest extent possible, is advantageous. For this reason,a tolerance element is provided in one embodiment of the presentinvention, which pre-tensions the output drive link and the input drivelink in the displacement axis of the input drive link when the outputdrive link and the input drive link are coupled to one another. In afurther development, the tolerance element tensions the guide linkdisposed on the output drive link against the input drive link, or thetolerance element disposed on the input drive link tensions the guideelement against the output drive link. In one embodiment, this toleranceelement can affect a precise transference of movements between theoutput drive link and the input drive link, and furthermore, duringcoupling and decoupling, can be displaced against its pre-tensioning,thus improving the coupling and decoupling. In one embodiment, thetolerance element has a tolerance element groove, which is preferably atleast substantially parallel to the groove in the interface, and inwhich the guide element engages when the output drive element and theinput drive element are coupled.

In a further development, the tolerance element is displaceably guidedon the input drive link and/or the guide element, and elasticallypre-tensioned against these. Likewise, it can be designed as an integralpart of the input drive link or the guide element, in particular bymeans of a hollow chamber, in which an integral leg can be inserted,which is supported on one or both sides.

In one embodiment, the tolerance element is displaceably guided andpre-tensioned parallel to a displacement axis of the displaceably guidedinput drive link. Additionally or alternatively, the tolerance elementcan be axially guided and pre-tensioned on the guide element. In oneembodiment, the groove and the guide element, in particular a rollerelement of the guide element, and/or the tolerance element, exhibitcomplementary chamfers, in particular in opposing directions. Inparticular by means of the axial alignments of such chamfers, in oneembodiment, the tolerance element can likewise (also) be pre-tensionedin displacement axes, and thus improve the guidance of the guide elementin the groove. One or more of the chamfers can be designed to be convex,in particular arched, in a further development, preferably in the mannerof an axial spherical roller bearing having asymmetrical barrel rollers.

In order to couple the output drive link and the input drive link duringor after connecting the drive module and the instrument shaft, or priorto, or to decouple them from one another during the releasing of thedrive module and instrument shaft, in one embodiment, the guide elementis mounted such that it is axially displaceable. As a result, it can beaxially inserted in, or removed from, the groove.

In a further development, the guide element, which is mounted such thatit can be axially displaced, is axially pre-tensioned. In this manner,in one embodiment it can be automatically inserted in the groove, and/orbe elastically secured therein.

In one embodiment, a connecting member is provided for the axialdisplacement of the guide element. In this manner, by rotating theoutput drive link, the guide element can first be displaced via theconnecting member, and thus be brought into, or out of, engagement withthe groove. The connecting member can have, in particular, one or morechamfers in the direction of rotation, on which a projection, preferablya collar, of the guide element slides up, by means of rotating theoutput drive link, and thus axially displaces the guide element. In afurther development, the connecting member has two chamfers in opposingdirections, spaced apart from one another in the direction of rotation,on which the projection slides up in rotational positions spaced apartfrom one another in the direction of rotation, and in this manner,axially displaces the guide element in opposing directions in thevarious rotational positions.

The rotational range for axial displacement of the guide elementadjoins, in one embodiment, a rotational range of the output drive linkfor actuating the input drive link coupled thereto. In this manner, by(further) rotating the output drive link, the input drive link can becoupled thereto or decoupled therefrom, and subsequently, or priorthereto, respectively, the input drive link can be actuated.

The guide element can be axially displaceably mounted and pre-tensionedon the output drive link or the input drive link. Likewise, the guideelement can be axially displaceably mounted and pre-tensioned togetherwith the output drive link or the input drive link. In particular, forthis purpose the output drive link can be displaceably mounted andpre-tensioned on the drive module and/or the input drive link on theinstrument shaft, preferably parallel to the rotational axis of theoutput drive link.

In order to couple the output drive link and the input drive link to oneanother during or after the connection of the drive module andinstrument shaft, or to decouple them, before or during the releasing ofthe drive module and instrument shaft, in one embodiment a guide wall ofthe groove has an opening for inserting the guide element by rotatingthe output drive link. As a result, the guide element can be rotatedinto the groove, or rotated out of the groove, respectively. The openingcan be formed, in particular, by a shortened leg of an open, orU-shaped, or otherwise closed or O-shaped pair of legs, which in turncan define the groove.

It can be advantageous, in particular for detecting a coordinate of adegree of freedom of the instrument shaft on the basis of the rotationalposition of the output drive link coupled thereto, if the output andinput drive links, or the guide element and groove, respectively, arecoupled to one another, at least substantially, in a one-to-onecorrespondence, such that each position of the input drive link in itsdisplacement axis precisely corresponds to a rotational position of theoutput drive link.

In particular, in one embodiment, the groove is therefore designed suchthat it is asymmetrical to the rotational axis of the output drive linkand/or a displacement axis of the input drive link. In a furtherdevelopment it extends, a least substantially, only as far as thisrotational axis.

In one embodiment, the input drive link is connected to exactly onepulling or pushing means, which is, at least substantially, parallel toa displacement axis of the input drive link. As a result, a movement ofthe input drive link can be precisely and readily converted to anactuation of a degree of freedom of the instrument shaft.

A surgical instrument according to the present invention can be used, inparticular, as a minimally invasive and/or robot-guided instrument. Forthis, in one embodiment, the instrument, in particular the instrumentshaft and/or the drive module, has an interface for connecting to arobot. According to one aspect of the present invention, a robot havingan instrument connected to it, preferably releasably, via an interface,is placed, accordingly, under protection, as it is disclosed here.Likewise, a drive module, or an instrument shaft, respectively, for asurgical instrument of this type is placed under protection, which hasone or more grooves or guide elements of the interface disclosed herefor the surgical instrument in order to couple corresponding guideelements, or grooves, respectively of the instrument shaft, or drivemodule, respectively.

According to one aspect of the present invention, during or after aconnecting of the drive module and the instrument shaft of a surgicalinstrument of the type described above, the guide element(s) is/arerotated into or axially inserted in the corresponding groove(s), inorder to couple the output drive link(s) and input drive link(s). Todecouple these, during or prior to the releasing of the drive module andthe instrument shaft, the guide element(s) is/are rotated out of thecorresponding groove(s), or axially removed therefrom.

BRIEF DESCRIPTION OF THE FIGURES

Further advantages and features can be derived from the dependent claimsand the embodiment examples. Shown are, in part schematically:

FIG. 1: a mechanical interface of an instrument assembly according toone embodiment of the present invention;

FIGS. 2 to 6: mechanical interfaces of instrument assemblies accordingto further embodiments of the present invention;

FIGS. 7A-7E: various embodiments of the front surfaces facing oneanother of the output drive elements and the input drive elements of themechanical interfaces in FIGS. 1 to 6;

FIGS. 8A-8C, 9, 10: compensation means for tolerance compensation;

FIGS. 11 to 15: various couplings of an instrument shaft-side drivetrain and an inventive mechanical interface;

FIG. 16: mechanical interfaces of instrument assemblies according tofurther embodiments of the present invention;

FIGS. 17A-17D, 18A-18D, 19A-19D: various embodiments of pins andcut-outs of the interface in FIG. 16;

FIGS. 20A-20B: an instrument assembly according to a further embodimentof the present invention;

FIG. 21: an instrument assembly according to a further embodiment of thepresent invention;

FIG. 22: a pin and a clamping means of the instrument assembly in FIG.21;

FIGS. 23A-23C: the steps of the strain-controlled coupling process forthe instrument assembly in FIG. 21;

FIGS. 24A-24B: mechanical interfaces of instrument assemblies accordingto further embodiments of the present invention;

FIGS. 25A-25C: the steps of the strain-controlled coupling process forthe instrument assembly in FIGS. 24A-24B;

FIGS. 26A-26C: various assemblies or joining directions, respectively,of an instrument shaft on a drive unit for an instrument assemblyaccording to further embodiments of the present invention;

FIGS. 27A-27C, 28, 29: mechanical interfaces of instrument assembliesaccording to further embodiments of the present invention;

FIGS. 30A-30C: mechanical interfaces of instrument assemblies accordingto further embodiments of the present invention, with a sterile barrier,having a cuff in the adjustment direction;

31A-31C: mechanical interfaces of instrument assemblies according tofurther embodiments of the present invention, with a sterile barrier,have a seal that can be displaced translationally without contactthereto;

FIGS. 32A-32B: a mechanical interface of an instrument assemblyaccording to a further embodiment of the present invention, with asterile barrier, which has an element extension that is releasablyconnected to an output drive element base or input drive element base;

FIGS. 33A-33B: an instrument assembly according to a further embodimentof the present invention, with an attachment element in the form of asterile adapter 4;

FIG. 34: a part of a surgical instrument according to one embodiment ofthe present invention;

FIG. 35: a signal-based linking of metering means in a metering assemblyfor the surgical instrument in FIG. 34;

FIG. 36: a control means, or method, respectively, according to oneembodiment of the present invention;

FIG. 37: a part of a robot-guided surgical instrument according to oneembodiment of the present invention in a partial section;

FIG. 38: a drive module and an input drive link assembly coupledthereto, of the surgical instrument in FIG. 37;

FIG. 39: a drive module and an input drive link assembly coupledthereto, according to a further embodiment of the present inventiondepicted in FIG. 38;

FIG. 40A: a drive module with a retraction assembly according to afurther embodiment of the present invention depicted in FIG. 38, in astate in which it is coupled to an input drive link assembly;

FIG. 40B: the retracted and locked down drive module in FIG. 40A;

FIG. 41: a drive module according to a further embodiment of the presentinvention depicted in FIG. 38;

FIG. 42A: a drive unit and an instrument shaft of a surgical instrumentaccording to a further embodiment of the present invention in a partialsection;

FIG. 42B: a drive unit and an instrument shaft of a surgical instrumentaccording to a further embodiment of the present invention depicted inFIG. 42A;

FIG. 43A: a drive unit and an instrument shaft of a surgical instrumentaccording to a further embodiment of the present invention depicted inFIG. 42A;

FIG. 43B: a drive unit and an instrument shaft of a surgical instrumentaccording to a further embodiment of the present invention depicted inFIG. 42A;

FIG. 44A: a drive unit and an instrument shaft of a surgical instrumentaccording to a further embodiment of the present invention depicted inFIG. 42A;

FIG. 44B: a drive unit and an instrument shaft of a surgical instrumentaccording to a further embodiment of the present invention depicted inFIG. 42A;

FIG. 45A: a drive unit and an instrument shaft of a surgical instrumentaccording to a further embodiment of the present invention depicted inFIG. 42A;

FIG. 45B: a drive unit and an instrument shaft of a surgical instrumentaccording to a further embodiment of the present invention depicted inFIG. 42A;

FIG. 46A: a drive unit and an instrument shaft of a surgical instrumentaccording to a further embodiment of the present invention depicted inFIG. 42A;

FIG. 46B: a drive unit and an instrument shaft of a surgical instrumentaccording to a further embodiment of the present invention depicted inFIG. 42A;

FIG. 47: a surgical instrument according to one embodiment of thepresent invention;

FIGS. 48A-48B: an interface of the surgical instrument in FIG. 47, in aperspective view;

FIGS. 49A-49B: steps for coupling a guide element to a groove in theinterface in FIGS. 48A-48B;

FIGS. 49C-49F: steps for actuating an input drive link by means of anoutput drive link of the surgical instrument in FIG. 47;

FIG. 50: an interface of a surgical instrument according to a furtherembodiment of the present invention, in a partial section;

FIGS. 51A, 51B: an interface of a surgical instrument according to afurther embodiment of the present invention in a perspective view (FIG.51A) and a partial section (FIG. 51B);

FIG. 52: an interface of a surgical instrument according to a furtherembodiment of the present invention in FIG. 51B in a correspondingmanner;

FIGS. 53A, 53B: an interface of a surgical instrument according to afurther embodiment of the present invention in various positions;

FIG. 54: an interface of a surgical instrument according to a furtherembodiment of the present invention; and

FIGS. 55A-55E: an interface of a surgical instrument according to afurther embodiment of the present invention in a view from above, in thedirection of a displacement axis (FIGS. 55A-55C), or in a perspectiveview (FIGS. 55D-55E), wherein an output drive link and an input drivelink are not coupled to one another (FIGS. 55A, 55B, 55D, 55E) or arecoupled to one another (FIG. 55C).

DETAILED DESCRIPTION

FIG. 1 shows a mechanical interface of an instrument assembly accordingto one embodiment of the present invention, having two output driveelements 10A, 10B of an output drive assembly running in oppositedirections, and a modular motor drive unit 1. These are coupled to twoinput drive elements 20A or 20B, respectively, of an input driveassembly for an instrument shaft 2. A sterile barrier 3 encases thedrive unit 1 and is disposed between this drive unit and the instrumentshaft 2.

Output drive and input drive elements 10A, 10B, and 20A, 20B,respectively, are inserted in the drive unit 1, or the instrument shaft2, respectively, such that they can be translationally displaced.

The output drive elements 10A, 10B are coupled to a coupling meansdesigned as a rocker 10C, such that a rotational movement by thecoupling means 10C, indicated by circular arrow in FIG. 1, is convertedto a translational movement of the elements 10A, 10B. The coupling means10C can be connected, for example, to an output drive shaft of anelectric motor for the drive unit 1, or can be coupled via a gearing(not shown).

In a similar manner, the input drive elements 20A, 20B are coupled to afurther coupling means designed as a rocker 20C, such that atranslational movement of the elements 20A, 20B is converted to arotational movement by the coupling means 20C. Pull cables or push rodsof the instrument shaft 2, which are axially spaced apart from oneanother, can be attached to the coupling means 20C, for example, bymeans of which a degree of freedom of an end effector is actuated, suchthat, for example, a scissors is opened, or a scalpel is rotated (notshown). Likewise, the rotational movement of the coupling means 20C canbe transferred, for example, via gearwheels, or—by means of a wormgearing—again converted into a translational movement.

Both output drive elements and input drive elements allocated thereto10A, 20A, and 10B, 20B, respectively, between themselves, as well as theoutput drive elements 10A, 10B and the coupling means 10C, as well asthe input drive elements 20A, 20B and the further coupling means 20C,are each coupled to one another by means of a one-sided linkage. One cansee that only pressure forces can be transferred by the coupling means10C to the output drive elements 10A, 10B, and by these to the inputdrive elements 20A, 20B, and by these, in turn, to the further couplingmeans 20C.

The output drive and input drive elements are designed as tappets in theembodiment, which are displaced along their longitudinal axes by meansof a linear actuator or a joint kinematic. The sterile barrier 3 islocated between the tappets. Because only pressure forces can betransferred with a pair of tappets, a closed kinematic loop is formed bythe second pair of tappets. The second pair of tappets is moved in theopposite direction of that of the first pair, such that drive forces canbe transferred in both directions. In general, therefore, in oneembodiment of the invention, a parallelogram kinematic is provided inthe mechanical interface.

The coupling of the instrument shaft to the drive unit has a simpledesign, and can, alternatively, occur along, or transverse to, themovement, or adjustment direction of the tappets 10A-20B. The tappets10A, 10B for the drive unit 1 are covered by the sterile barrier. Theinstrument shaft 2 is joined to the drive unit 1 such that the tappets10A, 20A, or 10B, 20B, respectively, are initially opposite one another,at a certain spacing. Subsequently the output drive-side is pushed tothe input drive-side. The angular position of the tilt lever, or rocker10C, 20C, is arbitrary thereby, because the positions of both sidesalign during the coupling process.

FIG. 2 shows a mechanical interface for an instrument assembly accordingto a further embodiment of the present invention. Features correspondingto those in the embodiment explained above are indicated with identicalreference symbols, such that in the following, only the differencesshall be addressed, and otherwise, reference is made to the overalldescription.

In the embodiment in FIG. 1, sliding contact occurs between the couplingmeans 10C, 20C and the tappets 10A, 10B, or 20A, 20B, respectively,wherein the frictional forces are a function of, among others, the leverposition and the contact surfaces, in particular their geometry andsurfaces. Therefore, in one embodiment of the present invention, as itis depicted by way of example in FIG. 2, a roller 30 is disposed in atleast a one-sided contact with a coupling means (in FIG. 2, by way ofexample: 10C, 20C) and the output drive and input drive elements (inFIG. 2, by way of example: 10A, 10B, or 20A, 20B, respectively), bymeans of which the friction can be reduced.

FIG. 3 shows a mechanical interface of an instrument assembly accordingto a further embodiment of the present invention. Features correspondingto those in the other embodiment are indicated by identical referencesymbols, such that only the differences shall be addressed below, andotherwise, reference is made to the overall description.

In the embodiments in FIGS. 1 and 2, the output drive elements 10A, 10Band the coupling means 10C, as well as the input drive elements 20A, 20Band the further coupling means 20C are each connected to one another bymeans of a one-sided linkage having sliding (FIG. 1) or rolling (FIG. 2)contact, respectively. In one embodiment, which is shown by way ofexample in FIG. 3, at least one output drive element (in FIG. 3, by wayof example: 10A, 10B) and one coupling means (in FIG. 3, by way ofexample: 10C), and/or at least one input drive element (in FIG. 3, byway of example: 20A, 20B) and one (further) coupling means (in FIG. 3,by way of example: 20C), on the contrary, are coupled to one another byat least one coupling rod (in FIG. 3, by way of example: 40), which isconnected in an articulated manner to the coupling means, or element,respectively.

FIG. 4 shows a mechanical interface of an instrument assembly accordingto a further embodiment of the present invention. Features correspondingto those in the other embodiments are indicated with identical referencesymbols, such that only the differences shall be addressed below, andotherwise, reference is made to the overall description.

In this embodiment, only one pair of tappets 10A, 20A for transferringforces is provided for the actuation of a degree of freedom. Instead ofa further pair of output and input drive elements, the input driveelement 20A is pre-tensioned against its adjustment direction by aspring 50. This returns the pair of tappets 10A, 20A against theadjustment direction, when an actuating force in an adjustment directionis removed, or, respectively, in the case of an actuating movement ofthe output drive element counter to this adjustment direction.

FIG. 5 shows a mechanical interface of an instrument assembly accordingto a further embodiment of the present invention. Features correspondingto those in the other embodiments are indicated with identical referencesymbols, such that only the differences shall be addressed below, andotherwise, reference is made to the overall description.

In one embodiment, which is shown by way of example in FIG. 5, a leastone coupling, in the manner of a spindle drive having sliding sleevesmoved in opposite directions, is formed between an output drive element(in FIG. 5, by way of example: 10A, 10B) and a coupling means (in FIG.5, by way of example: 10C). The coupling means, preferably designed as awinding spindle (in FIG. 5, by way of example: 10C) has, in oneembodiment, one section with right-handed threads and one section withleft-handed threads, on which, in each case, an output drive elementsits, designed as a spindle nut (in FIG. 5, by way of example: 10A or10B). By rotating the threaded spindle 10C, the spindle nuts 10A, 10Bare moved in opposite directions. The nuts can be secured againstturning by means of a guide rail 10D fixed in place in relation to thedrive unit, for example.

For purposes of clarification, a perspective partial section of theinterface is shown in the left side of FIG. 5, side views with differentsettings of the output drive elements 10A, 10B are shown in the middleand at the right, respectively.

FIG. 6 shows a mechanical interface of an instrument assembly accordingto a further embodiment of the present invention. Features correspondingto those in the other embodiments are indicated by identical referencesymbols, such that only the differences shall be addressed below, andotherwise, reference is made to the overall description.

In one embodiment, which is shown by way of example in FIG. 6, at leastone output element (in FIG. 6, by way of example: 10A, 10B) and onecoupling means (in FIG. 6, by way of example: 10C) and/or at least oneinput drive element (in FIG. 6, by way of example: 20A, 20B) and one(further) coupling means (in FIG. 6, by way of example: 20C) are coupledby a rack and pinion gearing. For this, in a further development, thecoupling means (in FIG. 6, by way of example: 10C, 20C) are designed aspinions, with which the output drive elements (in FIG. 6, by way ofexample: 10A, 10B), or the input drive elements (in FIG. 6, by way ofexample: 20A, 20B) designed as racks, mesh, in each case in oppositedirections, thus converting a rotational movement into a translationalmovement. Because they are disposed on opposite sides of the rack, theymove in opposing directions. When, in an advantageous furtherdevelopment, the input drive elements and/or the output drive elementsare pre-tensioned against their adjustment direction, or toward oneanother, respectively, backlash in the tooth engagements 10A-10C,10B-10C, 20A-20C, or 20B-20C, respectively, can be reduced or eliminatedthereby in an advantageous manner.

FIGS. 7A-7E shows various embodiments of the front surfaces of theoutput drive elements and the input drive elements 10A, 10B, or 20A,20B, respectively, facing one another, in the embodiments in FIGS. 1 to6, which are designed such that they are flat or convex and/or have aprojection for engaging in a cut-out in the other front surface: FIG. 7Ashows two flat front surfaces, or contact surfaces, which form a(one-sided linked) surface contact thereby, FIG. 7B shows a convex frontsurface and a flat front surface, which form a point contact, FIG. 7Cshows a spherical projection, which engages in a conical hole orcut-out, and forms an annular contact, FIG. 7D shows a conicalprojection, which engages in a conical hole or cut-out, and forms asurface contact, and FIG. 7E shows two convex front surfaces, or contactsurfaces, which form a point contact.

In order to ensure a transference precision and rigidity to the greatestpossible extent, deviations in the position and orientation of thecontact surfaces should be avoided. Possible causes of such deviationsare production and assembly tolerances, as well as deviations in thepositioning of the instrument in relation to the drive unit by the user.For this reason, in one embodiment of the present invention, at leastone one-sided linkage has a point contact between the output driveelement and the input drive element.

FIGS. 8A-8C, 9, 10 show compensation means for tolerance compensation.FIG. 8 shows a compensation for position and orientation deviations ofthe tappet-contact surfaces by means of flexibilities imposed thereon ina targeted manner. In one embodiment, which is indicated by way ofexample in FIG. 8A, a flexibility is formed by means of a flexibledesign of an output drive element and/or an input drive element (in FIG.8A, by way of example: 10A or 20A). Additionally or alternatively, aflexibility can be formed by means of an elastic deformation of thesterile barrier, as is indicated by way of example in FIG. 8B. Thesterile barrier is preferably produced, entirely or in part, from anelastomer. The flexible design of an output drive element and/or aninput drive element, as is shown in FIGS. 8A-8C, can be advantageouswith regard, in particular, to the transference behavior. In general, aflexibility in an embodiment of the present invention can have aprogressive spring characteristic, in order to thus be able tocompensate for smaller tolerances, and at the same time, to ensure arelatively rigid transference during larger actuations.

Additionally or alternatively, a flexibility can be provided in acoupling means, as is shown by way of example in FIG. 8C. Because of theclosed kinematic chain, this concerns, in principle, a staticover-determined system. In order to compensate for production andassembly tolerances in the kinematic chain, and to obtain a lack ofplay, length differences between the pair of tappets are compensated forby a flexible design of a coupling means.

In one embodiment, which is indicated by way of example in FIG. 9, acompensating means for tolerance compensation has a bearing that can bedisplaced in an adjustment direction (vertical in FIG. 9) or a bearingaxis of a coupling means that can be displaced in an adjustmentdirection (in FIG. 9, by way of example: 10C). For this purpose, in oneembodiment, this is rotatably mounted in a slide, which is disposedinside the drive unit such that it can be displaced therein. This thrustbearing enables a displacement in the direction of the tappet movement.A force is applied in this direction, for example, by means of a springor by means of a static adjustment, which pre-tensions the pair oftappets against one another in the interface (in FIG. 9, indicated bythe dotted force arrow).

FIG. 10 shows a compensation for length tolerances between the pair oftappets by means of flexibilities in the sterile barrier, as has alreadybeen explained above in reference to FIG. 8B. In one embodiment of thepresent invention, which is indicated by way of example in FIG. 10, aflexible compensation element 3.1 is integrated in the sterile barrier.By compressing this element, a pre-tensioning is built up in thekinematic loop, and at the same time, length differences are compensatedfor by means of different compressions. In particular, in order to avoidtoo much flexibility, which could be detrimental with respect to theregulating behavior, the compensation element 3.1 exhibits a progressivespring behavior in a further development. This can be obtained, inparticular, by means of an appropriate selection of the material and/orthe geometric design of the sterile barrier.

FIGS. 11 to 15 show, in particular, various advantageous couplings of aninstrument shaft-side drive train on an inventive mechanical interface,as is described above in reference to FIGS. 1 to 10, but in thefollowing in reference to the other figures. FIG. 11 shows a coupling ofa pull cable 60 to the input drive element thereby. In order to actuatea degree of freedom of the instrument shaft, in particular an endeffector (not depicted), in both, or opposite, directions, a kinematicloop is formed in the instrument shaft with the rotatably mounted rocker20C between the two tappets 20A, 20B. In the embodiment shown here, thetappets are each coupled to the rocker with a rotational thrust bearing20D. A cable pulley is permanently connected to the rocker, around whichthe pull cable is wound. In a further development a form-locking and/ormaterial bonded connection between the pulley and the pull cable is alsopossible. With an appropriate selection of the cable pulley diameter,optionally, an adjustment of the interface stroke to the necessary cablestroke can also be carried out. In addition to the depicted cylindricalcross-section of the cable pulley, other, in particular elliptical,cross-sections are also possible.

FIG. 12 shows a coupling of an instrument-side pull cable 60 on themechanical interface according to a further embodiment. In this case,the cable pulley, which forms an element of a coupling means as setforth in the present invention, is also provided with a gear toothing20E, which meshes with a toothed section of an instrument-side tappet(in FIG. 12, by way of example: 20B). The additional gear ratio of thisgearwheel stage enables, advantageously, an even better adjustment ofthe tappet stroke to the cable stroke.

In both embodiments in FIGS. 11, 12, the pull cable 60 is continuous. Inan alternative embodiment of the present invention, which is indicatedby way of example in FIGS. 13, 14 and 15, a degree of freedom can alsobe actuated by a pull cable with distinct ends (in FIG. 13, by way ofexample: 60) or by push rods (not shown), the ends of which can becoupled to input drive elements (in FIG. 13, by way of example: 20A,20B), or a coupling means coupled thereto. In one embodiment of thepresent invention, as is indicated by way of example in FIGS. 14, 15,the ends of the pull cable 60 are coupled via additional cable rockersthereby, to the mechanical interface, or its input drive elements 20A,20B, respectively. The cable stroke can advantageously be adjusted viathe ratios of the lever arms of each rocker. In order to avoid a changeto the necessary cable length, the lever ratios of both cable rockerscan be the same. In FIGS. 14, 15 the two bearing points of the cablerockers are depicted offset to one another, for better clarity. In oneembodiment, these bearings for the cable rockers can be coaxial to oneanother. In the embodiment in FIG. 14, the closed kinematic loop betweenthe output drive and input drive elements is formed by a furtherinstrument-side rocker, which is coupled, in each case, to theinstrument-side tappets 20A, 20B via a rotational thrust bearing 20D. Inthe embodiment in FIG. 15, this additional rocker is omitted, andinstead, the pre-tensioning of the interface is built up via the pullcable, by means of which a closed kinematic loop already exists. Inparticular, in this manner, according to one embodiment of the presentinvention, a pre-tensioning of the mechanical interface can also be usedin general for pre-tensioning an instrument shaft-side pull cable, bymeans of which the complexity of the instrument-side drive train isreduced. At this point, it should be expressly noted that in theembodiments shown here, the allocation of output drive and input driveelements is purely exemplary, and in particular, assemblies or featuresof an output drive element in one embodiment can also be combined withassemblies or features of an input drive element of another embodiment.Thus, for example in the embodiment in FIG. 14, instead of the inputdrive-side rotational thrust bearing 20D, analogous to the output driveside, an assembly, or coupling, respectively, with coupling rods (cf.output drive-side coupling rod 40 in FIG. 14) is also conceivable.

FIG. 16 shows a mechanical interface of the instrument assemblyaccording to a further embodiment of the present invention. Featurescorresponding to those in the other embodiments are indicated withidentical reference symbols, such that only the differences shall beaddressed below, and otherwise, reference is made to the overalldescription. In this embodiment, the interface has an output driveelement in the form of a pin 100 and an input drive element having acut-out 200, wherein the pin can be radially expanded in an elasticmanner in the cut-out by a clamping means. This embodiment is suited fortransferring tractive and pressure forces. In the following atranslational actuation or adjustment of the mechanical interface shallbe explained in an exemplary manner, although the mechanical interfacecan also be used for transferring rotational or superimposedtranslational and rotational movements.

The input drive pin 100 is guided and actuated in the drive unit 1 suchthat its position can be adjusted in a translational manner, andinserted in an instrument shaft-side cut-out in the form of a couplingsocket 200. The thin-walled sterile barrier 3 is disposed between thedrive unit and the instrument shaft.

The connecting of the input drive pin 100 and the coupling socket 200can be force-locking or form-locking, and can occur in relation to, orindependently of, the instrument drive. Advantageously, componentshaving a greater complexity and smaller tolerances can be disposed inthe drive unit, such that these interfaces are also advantageous, inparticular, for less expensive disposable instrument shafts. Thepositioning and attachment of the instrument shaft in relation to thedrive unit occur in a further development by means a separate functionalunit, as described below. The bearing for the coupling element ispreferably selected such that, for this reason, high demands on theshape and bearing tolerances are avoided, and the connecting of outputdrive elements and input drive elements occurs, at least substantially,without difficulty. The input drive pin is inserted, for this reason, ina further development, in the drive unit with a pentavalent thrustbearing, i.e. only displacements along the longitudinal axis arepossible. The positioning and orientation of the coupling socket in theinstrument shaft exhibits radial play, i.e. the coupling socket is notdistinctly guided in the radial direction. As long as the instrumentshaft is not coupled to the drive unit, the radial bearing ensures thatthe coupling sleeve is pre-positioned with sufficient precision, andcannot be released during manipulation and cleaning thereof. Once theinstrument shaft is coupled to the drive unit, this bearing no longerserves a function. At that point, the thrust bearing of the input drivepin also acts as the bearing for the instrument shaft-side input driveelement. In this manner, a connection is advantageously obtained withoutdifficulties, without placing a load on the two bearings. The bearingfor the coupling socket in the instrument shaft has two stops in afurther development, in the axial, or adjustment, direction. Thus, thenecessary working stroke can be individually determined for eachinstrument shaft, and the drive unit can be used for differentinstrument shafts.

A radial orientation of the coupling socket 200 in relation to the inputdrive pin 100 occurs automatically as a result of the geometric designof the coupling element. Thus, only a joining movement toward the inputdrive pin is necessary. As a result, instrument shaft replacement duringa surgical operation is advantageously facilitated, and can be executedquickly.

Various advantageous embodiments of input drive pins and couplingsockets are depicted in FIGS. 17A-17D, 18A-18D, in particular a flat(FIG. 17D), conical (FIG. 17C), spherical (FIG. 17B) and an elliptical(FIG. 17A) front surface of the input drive pin, can each be combinedwith different insertion geometries of the instrument shaft-sidecoupling socket, in particular a cylindrical (FIG. 18D) blind hole, inparticular with one or more steps (FIG. 18C), a chamfering (FIG. 18B) orrounding (FIG. 18A).

FIGS. 19A-19D show various couplings of the pin 100 and cut-out 200: inone embodiment, indicated by way of example in FIGS. 19A, 19B, and 19D,the pin and cut-out are coupled in a friction-locking manner by anelastic expansion of an input drive pin, designed in particular as asingle- (FIG. 19D) or multi-piece (FIGS. 19A, 19B) pin, which can havean elastic body (in FIGS. 19A, 19B, by way of example: 100.1), thediameter of which is increased by an elastic deformation by means of aclamping means (in FIGS. 19A, 19B, 19C: 100.2). In one embodiment,indicated by way of example in FIG. 19C, the pins and cut-outs arecoupled, additionally or exclusively, in a form-locking manner, throughan elastic expansion of a single- or multi-piece input drive pin. In oneembodiment, depicted in FIG. 19C by way of example, in combination withthe form-locking, a clamping means (in FIG. 19C, by way of example:100.2) has a conical external shape, and can be axially adjusted in thepin 100, in order to expand the pin radially from the inside. In theembodiment in FIGS. 19A, 19B, the clamping means 100.2 has a flangeinstead, for radially expanding the elastic pin by means of axialcompression. In the embodiment in FIG. 19D, the clamping means 100.2 isdesigned as a hydraulic or pneumatic element, and the pin is radiallyexpanded from the inside by pressurization thereof.

A sterile protective casing 3 is disposed between the pin and thecut-out, and enables the form-locking or friction-locking describedabove, due to its elasticity. As has been explained elsewhere, with thisembodiment, a movement of the (non-sterile) drive unit on a (sterile)instrument shaft does not pass through a hole in the sterile barrier,but rather, is transferred via the sealed sterile barrier, facilitatingthe sterile manipulation thereof.

The clamping movement, or the clamping means (in FIGS. 19A-19D, by wayof example: 100.2) can be actuated in relation to the instrument drive,or independently thereof.

FIG. 20A shows, by way of example, a drive unit 1 with three outputdrive elements in the form of pins, FIG. 20B shows an instrument shaft 2that can be coupled thereto, having three input drive elements, whichexhibit corresponding cut-outs. In one embodiment, a pin in an outputdrive or input drive element can be radially expandable in a non-elasticmanner, and for this purpose, can exhibit one or more radiallydisplaceably guided, preferably lamellar, separate bodies (in FIG. 20A,by way of example: 100.1), as is depicted by way of example in FIG. 20A.

FIGS. 21, 22, 23A-23C show cuts through a drive unit 1 and an instrumentshaft 2 coupled thereto, having a (crank) pin interface according to afurther embodiment of the present invention. Features corresponding tothose in the other embodiments are indicated with identical referencesymbols, such that only the differences shall be addressed below, andotherwise, reference is made to the overall description.

In particular, a clamping means drive in the form of an electric motor100.3 and a threaded spindle 100.2 are indicated schematically, such asa cylindrical screw drive, a clamping means, a crank pin 100, and aninstrument shaft-side coupling socket with a hole 200, for example. Thethreaded spindle 100.2, a ball or roller screw drive for example, ispowered by an electric motor 100.3 in a path-controlled manner. Thethreaded spindle is mounted in the drive unit 1 by means of a spindlebearing. A spindle nut meshing with the threaded spindle 100.2 isnon-rotatably connected to the crank pin 100. The crank pin is inserted,on its part, in a thrust bearing 100.5, which allows a translation onlyin the axial direction, and absorbs all radial forces and torques. Forthe friction-locking or form-locking (cf. FIGS. 19A-19D, in particular),the pin 100 has numerous separate bodies in the form of lamellar tensionlevers 100.1, which are uniformly distributed on the circumference ofthe crank pin. The tension levers 100.1 are rotatably mounted in thecrank pins 100 at the distal ends thereof (right side in FIG. 22), andas a result, are guided such that they can be displaced radially, suchthat a radial deflection of the tension lever results in a force- orform-locking clamping of the crank pin in the instrument-side couplingsocket. The deflection of the tension lever results, in apath-controlled manner, by means of the control contour, which can beintegrated in the threaded spindle, as indicated by way of example inFIGS. 21, 22, 23A-23C.

FIGS. 23A-23C show the steps for the path-controlled coupling procedurefor the output drive assembly and the input drive assembly to oneanother, by means of the mechanical interface, this being prior tocoupling the output drive element 100, and the input drive element 200(FIG. 23A), in which the clamping effect is obtained after inserting theinput drive pin into the coupling socket (FIG. 23B) and a maintaining ofthe clamping is obtained over the entire adjustment range through amechanical, positively driven, operation of the tension lever.

FIG. 23A shows the situation prior to the coupling. The drive unit 1 iscovered by a sterile casing 3, and the instrument shaft is secured tothe drive unit 1. The input drive pin 100 is inserted in a lowerboundary layer. A compression spring 200.1 in the instrument shaftsupports the coupling process, in that it ensures that the couplingsocket 200 is likewise located in a lower boundary layer. FIG. 23B showsthe situation immediately following the coupling. By extending the pin100 out of the drive unit 1, it is inserted into the coupling socket ofthe instrument shaft. Subsequently the tension lever 100.1 is forcedradially outward by the control contour on the threaded spindle 100.2,and thus establishes the friction- or form-locking connection thereby.As is shown in FIG. 23C, this mechanical connection is maintained bymeans of a mechanical positive guidance of the tension lever in theentire working range of the instrument shaft, with translationallyadjusted or actuated pins 100 in the embodiment example (vertical inFIGS. 23A-23C).

FIGS. 24A-24B show mechanical interfaces of instrument assembliesaccording to further embodiments of the present invention. Featurescorresponding to those in the other embodiments are indicated byidentical reference symbols, such that only the differences shall beaddressed below, and otherwise, reference is made to the overalldescription.

In the embodiment in FIGS. 24A-24B, the crank pin, or the clamping meansdrive, respectively, is force-controlled, the clamping force, contraryto the embodiments in FIGS. 21, 22, 23A-23C, 24A-24B, is not controlledby a positive guidance of the output drive element, or pin,respectively, applied by the actuator. The coupling between the outputdrive element and the input drive element is established by an elasticexpansion of the input drive pin 100, and can be force- or form-locking.By tightening a clamping mechanism, or means, respectively, the inputdrive pin is radially expanded. In the embodiment in FIGS. 24A-24B, theclamping means has a locking-ball mechanism for this, which can have,for example, in a variation that is not depicted, an expanding mandrel,an articulated lever mechanism, or a lock washer. In order to maintainthe clamping force over the entire adjustment range, in one embodimentof the present invention the clamping means is designed in general suchthat, as is indicated in FIGS. 24A-24B by way of example, it has akinematic dead center. This means, in the present case, in particular,that there is a kinematic range in which the clamping means remains openin a stable manner, or does not couple the output drive and input driveelements, respectively, and there is a further kinematic range,separated from the first by a dead center, in which the clamping meansremains closed in a stable manner, or couples the output drive and inputdrive elements. In the embodiment in FIGS. 24A-24B, the clamping meanshas numerous locking balls 100.6 distributed for this purpose on thecircumference of the input drive pin 100, and an actuating stud 100.2having a spherical head, the diameter of which is greater than the innerring defined by the not radially expanded locking balls. The clampingmeans is operated, or actuated, in that the actuating stud 100.2 isinserted into the input drive pin 100, and the locking balls 100.6 arethus pressed radially outward. As a result, a separate elastic body inthe form of an extension sleeve 100.1 is expanded in terms of itsdiameter, which can be notched or slotted, in order to keep theactuation force as low as possible. This sleeve prevents, in anadvantageous manner, point contact between the locking balls and thesterile barrier, which encases the pin 100 (not shown), and enables auniform pressure to be exerted over the largest possible contactsurface. As a result, the contact rigidity can be increased, and thesurface pressure to the sterile barrier can be minimized. The actuatingstud 100.2 is displaced beyond the dead center of the locking-ballmechanism, such that the locking balls are retracted slightly, radiallyinward, behind the spherical head of the actuating stud, in order tomaintain the clamping force in a stable manner.

A spindle drive, in particular, can serve as an actuator for actuatingthe output drive element or the input drive element, as is explained,for example, in reference to FIG. 22, wherein the clamping mechanism, orthe clamping means, can be actuated in relation to the actuator, orindependently thereof. In the first case, the insertion movement of thedrive unit acts on the actuating stud 100.2, as explained in referenceto FIGS. 23A-23C.

FIGS. 25A-25C show the steps for the force-controlled coupling processof the output drive assembly and the input drive assembly to one anotherby means of the mechanical interface in FIGS. 24A-24B, in a depictioncorresponding to FIGS. 23A-23C, to which supplementary reference ismade. FIG. 25A shows the situation prior to the coupling. The drive unit1 is covered by a sterile casing, and the instrument shaft is secured tothe drive unit. The input drive pin 100 is inserted in a lower boundarylayer. FIG. 25B shows the situation immediately following the coupling:in order to reliably insert the input drive pin into the coupling socketof the instrument shaft, the output drive element 100 is driven againstan end stop in the instrument shaft, and the coupling mechanism istriggered, or the clamping means is actuated, respectively. The lockingballs 100.6 are pressed radially outward by the actuating stud 100.2,and the mechanical connection of the output drive element and the inputdrive element is thus established. As shown in FIG. 25C, the mechanicalconnection is maintained in the entire working range of the instrument,because the dead center of the clamping mechanism has been overcome.

In an instrument assembly according to the present invention, theinstrument shaft can have a flange, in particular, wherein themechanical interface is disposed on a surface of this flange that facesthe end effector, faces away from the end effector, or a lateral surfaceof this flange. In other words, the drive unit 1 can be designed as a“back-loading,” “front-loading” or “side-loading” drive unit.

For clarification, advantageous joining directions for an instrumentshaft onto a drive unit of an instrument assembly are schematicallydepicted in FIGS. 25A-26C, according to various embodiments of thepresent invention. According to one embodiment, which is indicated byway of example in FIG. 26A, the instrument shaft is joined to the driveunit along the insertion direction of the instrument into the patient,which is referred to for this reason, as “back-loading.” In anotherembodiment, indicated by way of example in FIG. 26B, the instrumentshaft is joined to the drive unit counter in the insertion direction ofthe instrument into the patient, which is referred to, accordingly, as“front-loading.” In another embodiment, indicated by way of example inFIG. 26C, the instrument shaft is joined to the drive unit in adirection transverse to the insertion direction of the instrument in thepatient, which is referred to as “side-loading.” The instrument assemblyshown in FIG. 26A-26C can relate, in particular, to one of theembodiments explained in reference to one of the other figures, suchthat reference is made thereto for a description thereof.

FIGS. 27A-27C show a mechanical interface of an instrument assemblyaccording to another embodiment of the present invention, this being ina perspective view (FIG. 27A), and two sections in different strokepositions (FIGS. 27B, 27C). Features corresponding to those in otherembodiments are indicated with identical reference symbols, such thatonly the differences shall be addressed below, and otherwise, referenceis made to the overall description.

With this embodiment, a gap having a radial wave shape is formed betweenthe pin and the cut-out, in which a radially displaceable, axiallystationary, intermediate element assembly is disposed, for transferringa translational movement via a sterile barrier.

For this, the pin 100 is designed with a circumferential notching, andan instrument shaft-side coupling socket 200 is designed with acircumferential annular profile on the inside thereof. The pin and thecoupling socket are designed such that, in the joined state, apreferably equidistant wave-shaped gap is formed between thesecomponents. Rod-shaped intermediate elements 100.7 of an intermediateelement assembly are inserted in this gap, which support a cage sleeve100.8 in a spatially stationary manner, and can only be displacedradially. The thin, foil-like sterile barrier (not shown) is disposedbetween the coupling socket and the cage sleeve. By axially displacingthe pin 100 (vertically in FIGS. 27A-27C), the input drive-side part ofthe wave-shaped gap is pushed between the pin and the coupling socket.As a result of the kinematic constraints in the interface, the couplingsocket is pushed axially, or translationally, respectively, onto thepin, as is indicated in the series of figures, FIGS. 27B-27C. In afurther development, the intermediate elements of the intermediateelement assembly can be designed in the manner of sleeves, on the frontsurfaces of which balls are rotatably disposed in order to reduce thefrictional resistance.

FIGS. 28, 29 show mechanical interfaces of instrument assembliesaccording to further embodiments of the present invention. Featurescorresponding to those in other embodiments are indicated with identicalreference symbols, such that only the differences shall be addressedbelow, and otherwise, reference is made to the overall description.

In this embodiment, the mechanical interface has a tilt lever, in orderto transfer, in particular, a translational input drive movement via asterile barrier. A particular advantage of this concept is a simpledesign for the sterile barrier: it need only be designed for the tiltingmovement of the lever, and can, in a further development, bemanufactured in a simple manner as a plastic molded part, from athermoplastic elastomer or silicone, for example, in particular as adeep-drawn film. The tilting angle of the lever can be adjusted by arotary drive, in one embodiment, in particular an electric motor,optionally with a gearing interposed therebetween. The sterile barriercan encase the entire drive unit, and can also be pulled over the lever.In a further development that is not shown, the lever (in FIGS. 28, 29,by way of example: 1000) can, in general, be extended at its end facingaway from the contact, or the sterile barrier (below in FIGS. 28, 29),beyond its pivot bearing, and be coupled there to a drive, or aninstrument shaft-side drive train, respectively, such as a pull cable ora rod assembly, for example.

The tilt lever (in FIGS. 28, 29 by way of example: 1000) in oneembodiment is coupled, in general, in a form-locking manner with acoupling part, in particular it can be inserted in a groove of acoupling part, (in FIGS. 28, 29 by way of example: 2000) as is indicatedin the embodiments in FIGS. 28, 29. The tilt lever can be coupled, inparticular, with an output drive element of the output drive assembly ofthe drive unit, or represent such, and the coupling part, accordingly,can be coupled to an input drive element of the input drive assembly ofthe instrument shaft, or represent such, and the coupling part can becoupled, accordingly, to an output drive element of the output driveassembly of the drive unit, or represent such.

The coupling part 2000 can, in one embodiment, indicated by way ofexample in FIG. 28, can be guided by a thrust bearing 2000.1 such thatit can be adjusted in a translational manner. Thus, the rotationalmovement of the tilt lever 1000 is tapped into, for example, in theinstrument shaft, as a translational movement, or is exerted on thedrive unit as a translational movement. The kinematics of this interfaceis nonlinear, and is therefore, in a further development, compensatedfor in a computer, or in the drive unit control device.

Because a tilt lever in a further development is gimbal-mounted,movements in two degrees of freedom can also be transferred. For this,the illustration in FIG. 28, by way of example, is to be regarded as acutaway depiction in two planes that are perpendicular to one another.An interface with a tilt lever for actuating in three degrees of freedomcan be formed by means of the tilt lever being able to be displacedoptionally along its longitudinal axis as well (vertically in FIG. 28).

In another embodiment, indicated by way of example in FIG. 29, thecoupling part, coupled to the tilt lever in a form-locking manner, canlikewise be rotatably supported, or guided in a pivot bearing. Thisembodiment can also be expanded for actuation of two or more degrees offreedom, as is explained above in reference to FIG. 28.

The figures in FIGS. 30A-30C, 31A-31C, 32A-32B show instrumentassemblies according to further embodiments of the present invention,having a sterile barrier which—at least during a surgicaloperation—encases a drive unit, and is disposed between the drive unitand an instrument shaft coupled thereto by means of a mechanicalinterface. The drive unit, instrument shaft and/or mechanical interfacecan, in particular, be of the type in the other embodiments and figures,such that features corresponding to those in the other embodiments areindicated with identical reference symbols, and only the differencesshall be addressed below, and otherwise, reference is made to theoverall description.

The sterile barrier can in general be designed, in particular as asingle piece and/or as a film tube. In a further development, thesterile barrier is designed to be airtight, or encases the drive unit inan airtight manner, respectively. As is described below, in reference toFIGS. 30A-30C, 31A-31C, 32A-32B, a transference of an input drivemovement, or an actuation, respectively, from an output drive element toan input drive element does not occur through an opening in the sterilebarrier, but rather, is transferred via the sterile barrier that isclosed in this region.

In one embodiment, which is depicted in two variants in FIGS. 30A-30C,the sterile barrier has at least one pre-tensioned cuff in the region ofthe mechanical interface, in particular, one each in the region of eachoutput drive element, in an adjustment direction of the output drive andinput drive assemblies. The pre-tensioned cuff is designed as an elasticbellows in a further development, in particular as an elastomer bellows,preferably as a corrugated membrane (in FIG. 30A, by way of example:3.2) or as a corrugated bellows (in FIG. 30B, by way of example: 3.3),which is directly integrated in the sterile casing, or is an integralpart thereof, which, in particular, is originally formed therein, orshaped therein. In another embodiment, depicted as a variant in FIG.30C, the sterile barrier has at least one cuff in the region of themechanical interface, in particular one each in the region of eachoutput drive element, which is not pre-tensioned, in an adjustmentdirection of the output drive and input drive assemblies. This, at leastsubstantially, not pre-tensioned cuff is designed, in a furtherdevelopment, as a preferably elastic sleeve, in particular as athermoplastic or elastomer sleeve (in FIG. 30C, by way of example: 3.4),which is integrated directly in the sterile casing, or is designed as anintegral part thereof, in particular, is originally formed therein, orshaped therein.

FIG. 30A shows one embodiment as a flat corrugated membrane 3.2, FIG.30B as a corrugated bellows 3.3, the cross-section of which can be, inparticular, cylindrical or conical. Both bellows form cuffs in theadjustment direction (vertical in FIGS. 30A-30C), in which a returningpre-tension is imposed by the pleating, or the pre-formed corrugation,which compensates for the stroke occurring when the output drive element(in FIGS. 30A-30C, by way of example: 10A, 100 or 1000) is actuated inan adjustment direction.

In another embodiment, which is depicted in three variants in FIGS.31A-31C, the sterile barrier has at least one seal (in FIGS. 31A-31C, byway of example: 3.5) in the region of the mechanical interface, inparticular one each in the region of each output drive element, whichcan be translationally displaced without contact. This can be designed,in a further development, indicated by way of example in FIG. 31A, as anaxially displaceable gap seal. Likewise, in a further development,indicated by way of example in FIG. 31B, it can be designed as alabyrinth seal. As indicated by way of example in FIG. 31C, a seal thatcan be displaced translationally can preferably be telescoping, inparticular in the form of a one- or multi-step telescoping sleeve (inFIG. 31C, by way of example: three-step).

FIGS. 32A-32B show a further embodiment of the sterile barrier in theregion of the mechanical interfaces, in particular of at least one,preferably each, output drive element or input drive element, which isdistinguished by a very simple structure and production. The sterilebarrier has a sterile element extension for at least one, preferablyeach, output drive or input drive element, which can be releasablyconnected to an element base, which passes through the sterile barrierin a destructive manner. As indicated in the series of figures, FIGS.32A-32B, an output drive element base 11 passes through the sterilebarrier 3, by way of example, in a destructive manner, and the regionthat has passed through the barrier is releasably connected with asterile element extension 3.6 to an output drive element, as isindicated in the other embodiments and figures, for example, by thereference symbols 10A, 10B, 100 or 1000. Likewise, conversely, an inputdrive base 21 can also pass through the sterile barrier 3 in adestructive manner, and can be releasably connected with its regionpassing through the barrier, with a sterile element extension 3.6, to aninput drive element, as is indicated in the other embodiments andfigures, for example, by the reference symbols 20A, 20B, 200 or 2000.

In one embodiment, indicated by way of example in FIGS. 32A-32B, thesterile barrier has, in the regions of the element bases passing throughit, in each case one, preferably annular, reinforcement 3.7, formed, forexample, by plastic disks glued thereto, originally formed local wallthickness reinforcements, and/or local modifications of the material. Inthe middle of the reinforced region, the sterile barrier can again bedesigned as a thin membrane. After it has been encased, the drive unitis placed on a pin of the sterile extension 3.6, as described above. Forthis, the thin membrane of the sterile barrier is penetrated inside theannular reinforcement. The securing of the sterile extension can, inparticular, be friction-locking, material bonded, and/or form-locking,by means of a screw or bayonet connection, or it can also be obtained bymeans of a ball-lock bolt.

FIGS. 33A-33B show an instrument assembly according to a furtherembodiment of the present invention, having a sterile barrier 3,which—at least during a surgical operation—encases a drive unit 1, andis disposed between the drive unit and an instrument shaft 2 coupledthereto by means of a mechanical interface. The drive unit 1, instrumentshaft 2, and/or mechanical interface 3 can, in particular, be of thetypes in the other embodiments and figures, such that featurescorresponding to those in the other embodiments are indicated byidentical reference symbols, and only the differences shall be addressedbelow, and otherwise, reference is made to the overall description.

The instrument assembly has an attachment element in the form of asterile adapter 4, for the releasable attachment of the instrument shaft2 to the drive unit 1, which is to be, or is, disposed on a surface ofthe sterile barrier facing away from the drive unit.

The drive unit 1, which has numerous crank pins 100, by way of examplein the embodiment depicted in FIGS. 33A-33B, is enclosed in the sterilecasing 3. The covers for the output drive elements are integrated in thesterile casing in the embodiment depicted in FIGS. 33A-33B, by way ofexample as elastomer bellows, as has been explained above in referenceto FIGS. 30A-30C. After the drive unit is enclosed by the sterilebarrier, the sterile adapter 4 is secured from the outside onto thedrive unit in its sterile packaging. The adapter 4 thus does notinteract with the output drive elements 100, but rather, only makesavailable a mechanical interface for attaching the instrument shaft 2 tothe encased drive unit 1. This separation of the mechanical couplingfrom the output drive and input drive elements, on one hand (by means ofthe mechanical interface) and the mechanical attachment of the driveunit and the instrument shaft, on the other hand (by means of theattachment element, or the adapter, respectively), facilitates thesterile manipulation of the instrument assembly. In one embodiment,indicated by way of example in FIGS. 33A-33B, the adapter 4 can be, oris, connected to the instrument shaft and the drive unit in a form-and/or friction-locking manner, by means of locking, or clip,connections, for example, wherein the sterile casing 3 is also sealed,or free of holes, respectively, between the locking projections andcut-outs on the drive unit and adapter, thus ensuring sterility.

The preceding instrument assemblies are robot-guided, or configured forattachment to a manipulator of a manipulator surgical system,respectively, in a further development. In particular, for this thedrive unit 1, the instrument shaft 2, and/or an attachment element, oran adapter 4, respectively, can have a correspondingly configuredattachment interface, such as cut-outs, locking mechanisms, or suchlike,corresponding thereto.

In the above, components of an inventive instrument assembly, inparticular, have been described, wherein, however, methods for equippinga manipulator of a manipulator surgical system are also comprised in theinvention, in which a modular, motor powered, drive unit and aninstrument shaft are releasably connected to one another, and the outputdrive assembly and the input drive assembly are coupled to one anotherthereby, by means of the mechanical interface, as is shown in thevarious series of figures, FIG. 23A→FIG. 23B→FIG. 23C; FIG. 25A→FIG.25B→FIG. 25C; and FIG. 32A→FIG. 32B, as well as by the assembly arrowsin FIGS. 26A-26C and FIGS. 33A-33B.

FIG. 34 shows a part of a robot-guided minimally invasive surgicalinstrument according to one embodiment of the present invention, havinga drive module 10 and an instrument shaft 20, releasably connectedthereto in a manner that is not shown in detail, having an end effectorin the form of a moveable clamp, having two blades 2.1, 2.2. Oneembodiment of the invention shall be explained below, in particular,based on the blade 2.1; the construction and function of the blade 2.2is analogous thereto, such that reference in this respect is madethereto.

The blade 2.1 has a rotational degree of freedom q₁ with respect to theinstrument shaft 20. In order to actuate this degree of freedom, or toopen or close the blade 2.1 of the clamp, respectively, two drive trains21, 22 of an instrument shaft-side drive train assembly are connected inan articulated manner, in opposing directions, to the blade 2.1. Thedrive trains 21, 22 can, for example, be push rods, or tappets,respectively, which are mounted in the instrument shaft such that theycan be moved in a translational manner.

In order to actuate the push rods 21, 22 in opposing directions, theinput drive module has two drive trains 11, 12, acting in opposingdirections, which can be actuated in opposing directions by means of anelectric motor 13 of a drive in the input drive module. The drive trains11, 12 can likewise be push rods, or tappets, respectively, which aremounted in the input drive module such that they can be moved in atranslational manner.

A flexible sterile barrier 4 is, optionally, disposed in an interfacebetween the input drive module and the instrument shaft, by means ofwhich the instrument shaft-side drive train assembly and the input drivemodule-side drive train assembly can be releasably coupled to oneanother.

The drive train assemblies are translationally coupled in a one-sidedmanner: the push rods, or tappets 11 and 21, or 12 and 22, respectively,are translationally displaceable, and can only transfer pressure forcesvia the sterile barrier.

In order to ensure the force connection between the push rods, ortappets 11 and 21, and 12 and 22, which can only transfer pressureforces via the sterile barrier 4, the input drive module-side drivetrain assembly is pre-tensioned against the interface, as indicated inFIG. 34, by means of a bearing of the electric motor 13, pre-tensionedby means of a spring 5, with the drive train assembly coupled thereto.

A first metering means, in the form of a strain meter strip 31 of ametering assembly, is disposed on the first input drive module-sidedrive train 11 for registering a load F₁ in this drive train, and athird metering means, in the form of a strain meter strip 33 of ametering assembly, is disposed opposite the first metering means.

A second metering means, in the form of a strain meter strip 32 of themetering assembly, is disposed on the second input drive module-sidedrive train 12 for actuating the same degree of freedom q₁ of the blade2.1 of the end effector, for registering a load F₂ in this drive train,and a fourth metering means, in the form of a strain meter strip 34 ofthe metering assembly, is disposed opposite the second metering means.

As is shown in FIG. 35, the first metering means 31 in a first branch,the second metering means 32 in a second branch, the third meteringmeans 33 in a third branch, and the fourth metering means 34 in a fourthbranch, of a Wheatstone full-bridge circuit are coupled to one anotherwith signal-based technology.

For this, the second metering means 32 is interposed in a supply voltageU_(E) in series with the first metering means 31, the third meteringmeans 33 is interposed in the supply voltage in parallel to the secondmetering means 32, and the fourth metering means 34 is interposed in thesupply voltage in parallel to the first metering means 31.

Through the interconnection of the first and third, or second andfourth, metering means, respectively, to a linked output signal in theform of a bridge output voltage U_(A), bending loads, in particular, inthe drive trains 11, 12, which do not correspond to any active forces ofthe end effector, can be compensated for. By interconnecting the firstand third, or second and fourth, metering means, respectively, in thebridge output voltage U_(A), the shared pre-tension, in particular, ofthe input drive module-side drive train assembly, which acts on theopposing tappets 11, 12, and thus is not an active force actuating theblade 2.1, can be compensated for. With equalized bridges in theunloaded state, an at least substantially linear correlation isobtained, in the embodiment example, between the force actuating theblade 2.1, which has been freed of the pre-tension of the spring 5, i.e.is active, and twice the tension registered by the strain meter strip31, thus, advantageously, an additional, signal-based reinforcement ofthe registered load.

As is indicated in FIG. 34, the metering means 31-34 of the meteringassembly are oriented for registering axial pressure loads in thelongitudinal direction of the drive trains 11, 12, and disposed inradial cut-outs in the drive trains 11, 12.

In particular, in order to control the electric motor 13 and/or a manualteleoperation means, such as a mirroring instrument, for example (notshown), the active, or generalized loads F₁, F₂ are registered by themetering means 31-34, and the drive and the teleoperation means arecontrolled on the basis of these registered loads. In this manner, ahaptic feedback can be transmitted to the teleoperator, for example,pertaining to the clamping force exerted by the end effector on a lumen,or pertaining to, respectively, the resistance exerted by the lumen onthe clamps 2.1, 2.2.

FIG. 36 shows, for purposes of a more compact depiction, both a part ofa control means, as well as a method according to one embodiment of thepresent invention.

A control means 3, which can be implemented in a control for the robot,for example, which guides the minimally invasive surgical instrument inFIG. 34, receives the linked output signal U_(A) from the meteringassembly 31-34 (cf. FIG. 35 as well), which is, as explained above, inparticular, proportional to twice the load F₁ in the drive train 11. Thecontrol means 3 establishes a command S based on this load, registeredby the metering assembly, which it conveys, by way of example, to amotor control for the electric motor 13, or a teleoperation means in theform of a mirroring instrument (not shown), such that the motor 13implements a desired target force in the drive train 11, or,respectively, the mirroring instrument conveys a virtual load to theteleoperator, corresponding to the actual forces F_(E1), F_(E2) actingon the end effector.

A method, which is executed, for example, by the control means 3explained above, controls the drive 13, or the mirror instrument,respectively, in a corresponding manner, in that, in one step, itreceives the linked output signal U_(A) from the metering assembly31-34, and establishes the command S, based on this load registered bythe metering assembly, which controls, for example, the motor controlfor the electric motor 13, or the mirroring instrument, such that themotor 13 implements the desired target force in the drive train 11, orthe mirroring instrument, respectively, conveys the virtual load to theteleoperator, corresponding to the actual forces F_(E1), F_(E2) actingon the end effector.

FIG. 37 shows a part of a robot-guided, minimally invasive surgicalinstrument according to one embodiment of the present invention, in apartial section. The instrument has an instrument shaft 31 and a driveunit 30 releasably connected thereto.

The instrument shaft has an interface 42 for attachment to a robot 40,which is covered by a sterile casing 41.

The instrument shaft has numerous degrees of freedom, two of which areindicated, by way of example, in the embodiment example:

The instrument shaft has a tube 54, which is mounted in relation to aninstrument shaft housing 53 in a pivot bearing. Two cable pull drums 57c, 57 d running in opposite directions, act in opposite directions on agear wheel 58, and are coupled, in each case, to input drive links thatshall be explained in greater detail below, in the form of input drivetappets 37, 38 (cf. FIG. 38), which in turn, are actuated by outputdrive links in the form of output drive tappets 34, 35 (cf. FIG. 38).The output drive and input drive tappets 34/37, or 35/38, respectively,each form a pair of tappets, which are indicated in FIG. 37 by thenumerals 45 a-45 d. The tube 54 can be rotated in the pivot bearing 55in both directions by means of opposing actuations of the pair oftappets 45 c, 45 d, and thus, this degree of freedom of the instrumentshaft 31 can be actuated.

An end effector (not shown) is disposed on the end of the tube 54 thatis distanced from the drive unit, which has at least one degree offreedom in relation to the tube and/or at least one functional degree offreedom, such as the opening and closing of a forceps, for example. Twocable pull drums 57 a, 57 b, running in opposite directions, act inopposite directions on the end effector, and are coupled to input drivelinks in the form of input drive tappets 37, 38 (cf. FIG. 38), whichshall be explained in greater detail below, which in turn are actuatedby output drive links in the form of output drive tappets 34, 35 (cf.FIG. 38). A degree of freedom of the end effector can be actuated bymean of actuation of the pair of tappets 45 a, 45 b in opposingdirections.

The input drive tappets 37, 38 are mounted, in the embodiment example,in a translational manner, or displaceably, in an interface 56 a, or 56b, respectively, of the instrument shaft 31. In a variation, which isnot depicted, rotational or rotatable input drive shafts can, likewise,be coupled in a non-rotatable manner to the output drive shafts; oneembodiment of the present invention, having displaceable output driveand input drive links, is thus explained, merely by way of example,without being limited thereto.

The drive unit 30 has a housing 49, in which, by way of example, twoinput drive modules 47 a, 4 b for actuating the degrees of freedom,explained above, of the instrument shaft, are disposed. The input drivemodules each have a drive in the form of an electric motor 44 a, or 44b, respectively, and an output drive link assembly having twotranslationally moveable output drive links, which form the output drivetappets of the pair of tappets 45 a, 45 b, or 45 c, 45 d, respectively.

The actuation of the input drive tappets by the output drive tappetsshall be explained below in reference to FIG. 38. For this, the pairs oftappets 34/37 and 35/38 can likewise represent the aforementioned pairsof tappets 45 a and 45 b, or 45 c and 45 d.

The drive 44, which can be the drive 44 a or 44 b in FIG. 37, actuates,in opposing directions, the two output drive tappets 34 and 35, whichare displaceably mounted in a housing for the input drive module 47,which can be the input drive module 47 a or 47 b in FIG. 37. The outputdrive link and input drive link assemblies 34, 35 and 37, 38 are coupledin a one-sided manner in the embodiment example, via an optional,flexible sterile barrier 32. The input drive tappets 37, 38 are coupledto a rocker via coupling rods, which in turn, actuates the cable pulldrums 57.1, 57.2 in opposing directions, which can be the cable pulldrums 57 a, 57 b, or 57 c, 57 d in FIG. 37. The coupling rods and rockerform a gearing, which is encircled in FIG. 38 with a line consisting ofdots and dashes.

The input drive modules are, as indicated in FIGS. 37, 38, moveablymounted and pre-tensioned in the housing 49 for the drive unit 30, ineach case in a coupling direction (horizontal in FIG. 37; vertical inFIG. 38), against an input drive link assembly 37, 38. The couplingdirections for the two input drive modules 47 a, 47 b are parallel (cf.FIG. 37) to one another, and to the respective actuation directions inwhich the links can be moved for actuating the degrees of freedom of theinstrument shaft.

The input drive modules can have a compression spring, which restrainsthe input drive module in the housing, and pre-tensions it in thecoupling direction, or against the input drive link assembly,respectively. This is indicated in FIG. 37 with the numerals 46 a and 46b, and in FIG. 38, collectively, with the numeral 46.

In a variation shown in FIG. 41, the input drive module has, instead, amagnet assembly for pre-tensioning the input drive module.

In the embodiment example, the magnet assembly has an electromagnet 100on the housing 49 of the drive unit, on a side facing the instrumentshaft (below in FIG. 41) and a permanent magnet 101 opposite this, whichis disposed on the input drive module 47. Additionally, an electromagnet103 is disposed on the housing on a side facing away from the instrumentshaft (above in FIG. 41), and a permanent magnet 104 is disposedopposite this on the input drive module. Instead of the permanentmagnets 101 and/or 104, a magnetically soft region can also be provided,which can be attracted to the electromagnets 100 or 103 (when they aresupplied with current).

The activated electromagnet 100 magnetically attracts the input drivemodule 47 in the coupling direction (downward in FIG. 41) and thuspre-tensions the output drive link assemblies 34, 35 against the inputdrive link assembly (not shown in FIG. 41). Likewise, the activatedelectromagnet 103 can repel the permanent magnet 104 of the same pole,and thus pre-tension the input drive module 47 magnetically in thecoupling direction, against the input drive link assembly.

In a not depicted variation, one of the two electromagnets 100, 103 canbe omitted. Additionally or alternatively, in a variation, instead ofthe electromagnets 100 and/or 103, permanent magnets can also beprovided. The pre-tension effect of a permanent magnet 101 can bereduced by supplying the electromagnet 103 with current, in particular,it can be eliminated. If, in a variation, a permanent magnet is disposedin place of the electromagnet 103, having the opposite pole as that ofthe permanent magnet 104, or attracting this magnet, respectively, orthe permanent magnet 104 is replaced by a magnetically soft region ofthe input drive module, then, as a result, a permanent magnetic inputdrive module locking assembly for locking the retracted input drivemodule is implemented, which shall be explained in greater detail below,in reference to FIGS. 40A, 40B.

In the embodiment in FIG. 41, the magnet assembly has numerous,preferably non-magnetic, spacing elements 102, which prevent a directcontact between the permanent magnets or electromagnets 100 on thehousing of the drive unit with the magnetically soft or hard region, inparticular (further) permanent magnets 101 on the input drive module.Likewise, preferably non-magnetic, spacing elements 105 prevent a directcontact between the permanent magnets, or electromagnets 103 and themagnetically soft or hard region, in particular (further) permanentmagnets 104.

FIG. 39 shows an input drive module and an input drive link assemblycoupled thereto, according to another embodiment of the presentinvention corresponding to that depicted in FIG. 38. Featurescorresponding to those in the other embodiments are indicated withidentical reference symbols, such that reference is made to theirdescription, and only the differences shall be addressed below.

As is shown by way of example in FIG. 38, an input drive module 47 canbe moveably mounted directly in the housing 49 of the drive unit 30, inparticular in a form-locking manner, by means of one or more groovesand/or ribs, for example. Additionally or alternatively, as is shown,only by way of example, in the embodiment in FIG. 39, in one embodimentof the present invention, an output drive link assembly can be moveablymounted in the housing of the drive unit, wherein the drive, inparticular an input drive module housing 47.1, is supported therein,moveably mounted on the output drive link assembly, and is restrained,in particular in an elastic manner and/or by means of permanent magnetsand/or electromagnets, against the housing for the drive unit, and as aresult, is pre-tensioned in the coupling direction. In the embodiment inFIG. 39, the output drive tappets 34, 35 are each moveably mounted inthrust bearings in the housing 49 for the drive unit. A housing 47.1 forthe input drive module, in which the input drive acting on the outputdrive tappets 34, 35 in opposing directions is supported, is restrainedby a magnet assembly or compression springs 46 against the housing 49for the drive unit, and as a result, is pre-tensioned in the couplingdirection (vertically downward in FIG. 39).

FIGS. 40A, 40B show an input drive module and an input drive linkassembly coupled thereto according to another embodiment of the presentinvention corresponding to that in FIG. 38. Features corresponding tothose in the other embodiments are indicated by identical referencesymbols, such that reference is made to their description, and only thedifferences shall be addressed below. FIG. 40A shows the input drivemodule thereby, in a state in which it is coupled to the input drivelink assembly, FIG. 40B shows the retracted, and locked in place, inputdrive module.

As explained above in reference to FIG. 41, the input drive module 47can be retracted against the pre-tensioning by means of a selective, inparticular a controlled, supplying of current to a magnet assemblyhaving at least one electromagnet 100 and/or 103. This can, inparticular, facilitate a coupling and decoupling of the drive unit toand from the instrument shaft, because the (full) pre-tensioning doesnot have to be overcome, in particular manually, thereby. Thus, a magnetassembly supplied with current in a corresponding manner, as has beenexplained in reference to FIG. 41, represents a magnetic retractionassembly for retracting the input drive module against thepre-tensioning.

In the embodiment in FIG. 40, the drive has an output drive means in theform of a rocker 59, to which the output drive tappets 34, 35 arecoupled in opposing directions by means of coupling rods. In order toactuate a degree of freedom of the instrument shaft, the drive requiresonly a limited angular range, which thus defines an actuating range. Bythis means, a retraction range is delimited by a mechanical stop 60 forthe rocker 59, which extends for this purpose out of a housing for theinput drive module 47.1.

As long as the input drive moves the rocker within the actuation range,as indicated in FIG. 40A, the output drive tappets are actuated inopposing directions. When the end of the retraction range has beenreached, the rocker 59 rests against the mechanical stop 60, as shown inFIG. 40B. By rotating the rocker 59 further into the retraction range,the input drive displaces the input drive module against the pre-tensionof the spring element 46 via the rocker 59, and thus pulls the inputdrive module back, by means of a motor, against the pre-tensioning. Ina, not shown, variation, the stop 60 does not interact with the rocker59, but rather, with one or both of the tappets 34, 35.

As is depicted in FIG. 41, the retraction assemblies 59, 60 can also becombined with a magnetic pre-tensioning, in particular by means of amagnet assembly having permanent magnets 101 and/or 104.

In particular, in order to relieve the input drive, an input drivemodule locking assembly for locking the retracted input drive module inplace can be provided. This has, in the embodiment in FIG. 40B, aspring-loaded and manually or automatically releasable latch 61, bymeans of which the output drive module, which has been retracted againstthe pre-tensioning, is secured in a form-locking manner.

The input drive module locking assembly can also be magnetic. When amagnet, as explained in reference to FIG. 41, in particular a permanentmagnet 101, magnetically attracts a magnetically soft region or apermanent magnet 104 of the opposite pole, on the input drive module,the (more strongly pre-tensioned) input drive module can be magneticallylocked in place. In one embodiment of the present invention, theretraction assembly is also designed to release the locking, or toadjust the input drive module in the coupling direction. For this, inone embodiment, a mechanical counter-stop can be provided, in general,against which the output drive means is supported, when it is adjustedin a feed range differing from the actuation and retraction range. Inthe embodiment in FIG. 41, a corresponding counter-stop 106 is disposedon the housing for the drive unit, and defines a feed range differingfrom the actuation range and the retraction range defined by the stop60. When the feed range has been reached, the rocker 59 rests, asdepicted in FIG. 41, against the mechanical counter-stop 106. By furtherrotating the rocker 59 into the feed range, the drive displaces theinput drive module, via the rocker 59, against the locking action of themagnet assembly 103, 104 in the coupling direction (vertically downwardin FIG. 41). Here as well, in a variation, the stop 60 can interact withone or both of the tappets 34, 35, instead of with the rocker 59.

As is discernable, in particular, in FIGS. 42A-42B, 43A-44B, 44A-44B,45A-45B, and 46A-46B, the coupling direction (horizontal in thefigures), in which the input drive module 47A, 47B is moveably mountedand pre-tensioned in the housing 49, forms an angle with thelongitudinal axis of the instrument shaft 31 (vertical in the figures),which is substantially 90 degrees.

In the following, with reference to FIGS. 42A-42B, 43A-43B, 44A-44B,45A-45B, 46A-46B, a mounting element for the instrument shaft, for aform-locking, releasable attachment of the drive unit shall be explainedaccording to various embodiments of the present invention. Featurescorresponding to those in other embodiments are indicated by identicalreference symbols, such that reference is made to their description, andonly the differences shall be addressed below. The figures show, in eachcase, a part of the instrument shaft, with its mounting element, and thedrive unit, still separated therefrom, wherein an insertion directionfor the drive unit in the mounting element is indicated by a movementarrow.

The mounting element 80 in the embodiment in FIG. 42A has a chamferedinsertion opening 140 for inserting the drive unit 30 in an insertiondirection, wherein the insertion direction is parallel to thelongitudinal axis of the instrument shaft (vertical in FIG. 42A). Theinsertion opening 140 is disposed on the side facing away from theinstrument shaft (above in FIG. 42A).

The moveable input drive links of the input drive link assembly 45.2 ofthe instrument shaft, such as the input drive tappets 37, 38, by way ofexample, are perpendicular, as explained above in reference to FIGS.38-41, to the longitudinal axis of the instrument shaft 31, as far asits mounting element 80, wherein the interface, or the contact plane forthe input drive link assembly 45.2 is parallel to the longitudinal axis.

In the embodiment in FIG. 42B, the input drive link assembly 45.2 of theinstrument shaft 31 is disposed in a recess 142. Additionally oralternatively, the output drive link assembly 45.1 of the drive unit 30,the output drive tappets 34, 35, for example, as explained above inreference to FIGS. 38-41, is disposed in a recess 143, when it isretracted by the retraction assembly against the pre-tensioning. Afterinserting the drive unit 30 in the mounting element 80, and unlockingthe retraction assembly, or building up a pre-tension, respectively, thepre-tensioned output drive link assembly 45.1, which then protrudes outof the recess 143, makes contact with the input drive link assembly 45.2of the instrument shaft 31.

The embodiment in FIG. 43A corresponds substantially to that in FIG.42A. For the form-locking attachment of the drive unit 30 in themounting element 80 of the instrument shaft 31, a bayonet coupling,having at least one projection 151 on the housing 49, is provided, whichengages in a cut-out 150 in the mounting element 80 as a result ofrotating the drive unit. Likewise, the projection 151, in a variation,can engage in the cut-out 150 in the mounting element 80 as a result ofa displacement (horizontally, toward the left in FIG. 43A), instead ofby means of a rotation, wherein this displacement preferably occurs as aresult of applying the pre-tensioning force. The user thus pushes thedrive unit (vertically from above in FIG. 43A) into the mountingelement. Subsequently, a coupling procedure is initiated, in particularmanually or automatically, in which the pre-tensioning force is appliedto the interfaces. As a result, the projection 151 on the drive unit ispushed into the cut-out 150, perpendicular to the insertion direction,and thus the drive unit is locked in place in a form-locking manner.

The embodiment in FIG. 43B corresponds substantially to those in FIGS.42A, 43A. The mounting element 80 in this embodiment has a multi-partform-locking guide for inserting the drive unit 30 in the insertiondirection. The guide has numerous guide grooves 152, which interact withcorresponding projections 153 on the housing 49 for the drive unit 30 ina form-locking manner, in order to attach the housing in a form-lockingmanner in the mounting element 80 of the instrument shaft 31. The guidegrooves 152 are substantially L-shaped, such that the drive unit in turncan be secured in the mounting element in a form-locking manner by meansof a rotation thereof. As with the bayonet coupling of the embodimentaccording to FIG. 43A, the drive unit, after it has been inserted in themounting element, is rotated, and as a result, secured in a form-lockingmanner, such that it is pre-tensioned counter to the insertiondirection, by means of a corresponding oversize, or an elastic springelement (not shown), in order to thus counteract, in a friction-lockingmanner, a reverse rotation, and thus a release of the drive unit.Likewise, in a variation such as the variation explained above inreference to FIG. 43A, the projections 153 can be displacedperpendicular to the insertion direction, as a result of a displacementin the short leg of the cut-out 152, wherein this displacement in turn,preferably occurs by applying the pre-tensioning force. The user thuspushes the drive unit (vertically from above in FIG. 43B) into themounting element. In doing so, the projections 153 slide in the long legof the L-shaped cut-outs 152, as far as the bend thereof. Subsequently acoupling procedure is initiated, in particular manually orautomatically, in which the pre-tensioning force is applied to theinterfaces. As a result, the projections 153 on the drive unit arepushed into the cut-outs 152, perpendicular to the insertion direction,and thus the drive unit is locked in place in a form-locking manner.

The embodiment in FIG. 44A corresponds substantially to that in FIG.43B, wherein here, a guide rib 161, which extends in the insertiondirection, is inserted in a complementary guide groove 160 on themounting element 80, and will be, or is, secured therein, in afriction-locking manner, for example. In one embodiment of the presentinvention, as is depicted by way of example in FIG. 44A, the mountingelement has, in general, in addition to the insertion opening, a furtheropening (left in FIG. 44A), in particular in order to improve asignal-based and/or energy-based connection (not shown) for the driveunit.

In the embodiment in FIG. 44B, the insertion direction is perpendicularto the longitudinal axis of the instrument shaft. The insertion openingis disposed on the side facing away from the instrument shaft (left inFIG. 44B).

In the embodiment in FIG. 44B, a drive unit locking assembly is providedfor the form-locking locking in place of the drive unit 30 in themounting element 80, in the form of a moveable, pre-tensioned latch 167,which catches in the drive unit 30 when it is placed in the mountingelement 80. Although it is not depicted, a drive unit locking assemblyof this type, or similar thereto, can also be provided in the otherembodiments, in particular in addition to, or alternatively to aform-locking securing, in particular a bayonet coupling, or afriction-locking securing.

The mounting element 80 in the embodiment in FIG. 44B has one or moreguide ribs 165, which engage in corresponding guide grooves 166 in thehousing 49 for the drive unit 30. As is described in reference to FIG.42B, the input drive link assembly 45.2 is disposed in a recess 164.

The embodiment in FIG. 45A corresponds substantially to that in FIG.44B, wherein the insertion opening can be closed by a pivotable lid 170,in order to secure the drive unit 30 against the insertion direction ina form-locking manner.

In the embodiment in FIG. 45B, the mounting element 80 can be pivoted inrelation to the longitudinal axis of the instrument shaft. This makes itpossible, as indicated in FIG. 45B by the movement arrow, to firstinsert the drive unit 30 into the mounting element that has been pivotedto a mounting position (cf. FIG. 45B), and then to pivot the mountingelement into a locking position, wherein the drive unit is then securedin a form-locking manner in this locking position in the mountingelement.

In the embodiment in FIG. 46A, the drive unit 30 has a convergentpositive displacement means for forcing the input drive link assembly ofthe instrument shaft into the mounting element of the instrument shaftwhen the drive unit is being inserted. The convergent positivedisplacement means in the embodiment in FIG. 46A has a convex, inparticular a chamfered or elliptical, surface, which converges in afirst section 180 a in the insertion direction, and thus pushes backinput drive links of the input drive link assembly 45.2 that protrudefurther than normal in a form-locking manner. A surface 180 b divergingin the insertion direction, likewise convex in the embodiment in FIG.46A, adjoins the surface 180 a converging in the insertion direction, inorder to also push back input drive links that protrude from themounting element 80 when removing the drive unit 30.

In the embodiment in FIG. 46B, the drive unit 30 has, on the contrary, amoveable positive displacement means, in the form of numerous rotatablerollers 181 a, 181 b, which pushes back input drive links of the inputdrive link assembly 45.2 that protrude further than normal during theinsertion, and thus levels the input drive link assembly. After rollingover the rollers 181 a, 181 b, or the convex surface 180 a, the inputdrive links then project, at least substantially, to the same degreetoward the mounting element on the instrument shaft.

FIG. 47 shows, schematically, a surgical instrument according to oneembodiment of the present invention, having an instrument shaft 20. Theinstrument shaft has a rigid, articulated, or flexible tube 22, on thedistal end of which an end effector 21 is disposed, having one or morefunctional and/or kinematic degrees of freedom. In a proximal instrumenthousing 23 of the instrument shaft, an input drive module 25 isreleasably connected, at an interface 24, to the instrument shaft. Thetube 22 can be secured to, or rotatably mounted on, the instrumenthousing 23, such that the tube 22 has one degree of freedom about itslongitudinal axis.

FIGS. 48A, 48B show this interface in different perspectives. For abetter overview, only a few components of the input drive module 25 andthe instrument shaft 20 are depicted, and are thus indicated with anapostrophe (′). In particular, only one drive train for actuating adegree of freedom of the instrument shaft is shown; further drive trainshave an analogous construction, and are disposed, for example, parallelto the shown drive train.

Each drive train has an actuator in the form of an electricmotor-gearing unit 31′, the output drive shaft of which represents anoutput drive link of the input drive module that can rotate withoutlimits.

An input drive link 32′ is coupled to this output drive link in a mannerdescribed below, which is inserted in a form-locking manner in a thrustbearing 34′ such that it can be displaced in a displacement axis B′ inthe instrument shaft.

The input drive link is connected to the end effector 21 by a pullingmeans, or a push rod 36, (not shown) in order to actuate the input drivelink, wherein the push rod is parallel to the displacement axis B′. Theinput drive link can be displaced between two end stops 37.1, 37.2 (cf.FIGS. 53A-53B, not shown in FIGS. 48A-48B).

A linear groove 33′ is disposed on the input drive link, which isperpendicular to the displacement axis B′. A guide element 30′ isdisposed eccentrically on the rotatable output drive link, and insertedin the groove such that it can be displaced, when the output drive linkand the input drive link are coupled to one another. The rotational axisfor the rotatable output drive link is perpendicular to the displacementaxis B′ of the displaceably guided input drive link and the groove.

The guide element 30′ has a pin, on which a roller element in the formof a ball race is mounted, in a sliding or rolling manner. In avariation, instead of this, a roller element without an outer race canalso be disposed on the pin.

FIGS. 49A-49B show the steps for coupling the guide element to thegroove, and FIGS. 49C-49F show the steps for the actuation of the inputdrive link by the output drive link.

In FIG. 49A, the input drive module and the instrument shaft areconnected to one another, wherein the output drive link and the inputdrive link 32′ are not yet coupled to one another. By rotating theoutput drive link (cf. movement arrow A′ in FIGS. 48A, 49C) the guideelement 30′ rotates through an opening in the, in FIGS. 49A-49F, upper,guide wall of the groove 33′ into the groove (cf. movement arrow F inFIG. 49A) and thus couples—initially in a one-sided manner—the outputdrive link and the input drive link (FIG. 49B). When the output drivelink is rotated further (cf. movement arrow A′ in FIG. 49C), the guideelement 30′, which is now inserted in the groove 33′, pushes the inputdrive link 32′ into the thrust bearing 34′ in its displacement axis B′.In FIGS. 49D-49F it is clear how the rotating of the output drive linkdisplaces the input drive link on both sides along its displacement axisB′, and can thus actuate the end effector: by rotating the output drivelink and the guide element 30′ eccentrically disposed thereon, in thedirection of, or opposite, respectively, the movement arrow A′ in FIG.49C, the input drive link 32′ can be displaced in its displacement axisB′ in both directions (up or down in FIGS. 49A-49F), and thus, anintracorporeal degree of freedom of the instrument is actuated via thepulling means, or the push rod 36, respectively (cf. FIGS. 48A-48B).

In the embodiment in FIGS. 48A-48B, 49A-49F, the (upper, in the figures)guide wall of the groove has an opening for inserting the guide elementby rotating its output drive link, which is formed by a shortened leg ofan open, or U-shaped pair of legs, which in turn defines the groove.

FIG. 50 shows, in a manner corresponding to that of FIGS. 48A-48B, aninterface of a surgical instrument according to a further embodiment ofthe present invention, in a partial section. As is the case in FIGS.48A-48B, for a better overview, only some of the components of an inputdrive module 125 and instrument shaft 120 are depicted, in particularonly one drive train for actuating a degree of freedom of the instrumentshaft is shown, while further drive trains can be constructed in ananalogous manner, and be disposed, for example, parallel to the showndrive train.

Each drive train has an actuator in the form, for example, of anelectric motor-gearing unit 131, the output drive shaft of whichrepresents an output drive link of the input drive module, which canrotate without limit.

An input drive link 132 is linked to this output drive link in a mannerdescribed below, which is inserted, in a form-locking manner, in athrust bearing (not shown) in the instrument shaft that can be displacedin a displacement axis B″, and is connected to the end effector by apulling means or a push rod, which is parallel to the displacement axisB″.

A linear groove (cut in FIG. 50) is disposed in the input drive link,which is perpendicular to the displacement axis B″ and an axis of aguide element 130, which is disposed eccentrically on the rotatableoutput drive link and displaceably guided in the groove, when the outputdrive link and the input drive link are coupled to one another. Therotational axis of the rotatable output drive link is perpendicular tothe displacement axis B″ of the displaceably guided input drive link andthe groove. The eccentric guide element 130 is supported on a frame 139of the actuator 131 via a radial bearing 140.

A tolerance element 132.3 is provided in the embodiment in FIG. 50. Thetolerance element is displaceably guided on the input drive link 132parallel to its displacement axis B″, and pre-tensioned in an elasticmanner against it by means of a spring element 132.4. In this manner,the tolerance element 132.3 pre-tensions the output drive link and theinput drive link in the displacement axis B″ of the input drive link,when the output drive link and the input drive link are coupled to oneanother.

The tolerance element has a tolerance element groove, which is parallelto the groove in the input drive link 132, and through which the guideelement 130.2 passes, when the output drive element and the input driveelement are coupled.

In the embodiment in FIG. 50, the guide element has a rotatably mountedroller element in the form of a ball race 130.2, which is mounted in asliding or rolling manner, for making contact to the groove in the inputdrive element. A further rotatably mounted roller element in the form ofa ball race 130.1, mounted in a sliding or rolling manner, is disposedaxially adjacent thereto for making contact with the tolerance elementgroove. In a variation, instead of this, roller bearings without anouter race can also be provided.

The guide element 130 is mounted in the output drive link such that itis axially displaceable. As a result, it can be axially inserted in, orremoved from, respectively, the groove in the input drive element andthe tolerance element groove. It is pre-tensioned against the grooves bymeans of an axial spring (not shown), such that it enters these groovesautomatically.

A connecting member 138 for axial displacement of guide elements isconnected to the frame 139 in a non-rotatable manner. It has a chamferin the direction of rotation, on which collar of the guide elementslides up. In this manner, by rotating the output drive link in thedirection indicated by a movement arrow A′″ in FIG. 50, via theconnecting member 138, the guide element 130.2 can be axially displaced(toward the left in FIG. 50) and thus taken out of engagement with thegrooves. In a variation not shown here, the guide element can be axiallydisplaced in opposing directions by means of the connecting member, inrotational positions that are spaced apart from one another, and thus,is not brought out of engagement, but rather, is also brought intoengagement with the grooves. For this, the connecting member can have afurther chamfer, corresponding to the chamfer depicted in FIG. 50, whichruns in the opposite direction, and is spaced apart therefrom in thedirection of rotation, which pushes the collar of the guide elementaxially into the groove when the output drive link is rotated in thedirection opposite A′″. In this case, a pre-tensioning can be reduced oreliminated by an axial spring.

FIGS. 51A, 51B show, in a perspective view (FIG. 51A) and a partial view(FIG. 51B), an interface of a surgical instrument according to anotherembodiment of the present invention. This corresponds substantially tothe embodiment in FIG. 50, such that reference is made to itsdescription, and only the differences shall be addressed below.

In the embodiment in FIGS. 51A-51B, the tolerance element is designed asan integral part of the input drive link 132″, this being in a hollowchamber 333.3, in which an integral leg 333.1 can be inserted, which issupported on both sides (left, right in FIG. 51A).

In the partial section in FIG. 51B, the guide element 330 can be seen,which is guided by a roller bearing 330.2 in the groove 333.2 of theinput drive link 132″. In addition, the guide element 330 is supportedon the leg 333.1 of the integral tolerance element via a further rollerbearing 330.1, which pre-tensions the guide element 330 and thus theoutput drive link, in which it is mounted, and the input drive link 132″in a displacement axis of the input drive link (vertical in FIG. 51B).

FIG. 52 shows an interface, in a manner corresponding to that in FIG.51B, of a surgical instrument according to another embodiment of thepresent invention, in a partial section. This corresponds,substantially, to the embodiment in FIG. 50, such that reference is madehere to its description, and only the differences shall be addressedbelow.

In the embodiment in FIG. 52, an inner race 230.3 of a roller bearingwithout an outer race, having roller elements 130.1, 130.2, is disposedon a pin 130′ of the guide element. The right-hand roller element 130.2in FIG. 52 functions thereby as a tolerance element, which pre-tensionsthe guide element and thus the output drive link against the input drivelink 132′ in a displacement axis B^(IV) of the input drive link, whenthe output drive link and the input drive link are coupled to oneanother.

For this, the left roller elements 130.1, in FIG. 52, of the guideelement and the tolerance element 130.2 have chamfers in opposingdirections, which are complementary to the opposing chamfers 233.1,233.2 of the input drive element 132′. The tolerance element 130.2 isguided in an axially displaceable manner on the inner race 230.3 of theguide element, and pre-tensioned against it by means of a spring element230.4. By means of the axial blocking of the tolerance element 130.2 bythe chamfer, as a function of the spring element, it pre-tensions theoutput drive link and the input drive link 132′ in the displacement axisB^(IV).

As explained above, the left ball race 130.1 in FIG. 52, which can bemounted in a sliding manner, or can slide, respectively, radiallyoutside on the input drive link 132′ and/or radially inside on the innerrace 230.3, and the right tolerance element 130.2 in FIG. 52, which canbe mounted in a sliding manner, or can slide, respectively, radiallyoutside on the input drive link 132′ and/or radially inside on the innerrace 230.3, represent roller bodies as set forth in the presentinvention, and the roller bodies 130.1, 130.2 and inner race 230.3collectively thus form a roller bearing without an outer race, as setforth in the present invention. In addition, or alternatively, to arotatability, or sliding support, respectively, of the roller elements130.1, 130.2 with respect to the input drive link 132′ and/or the innerrace 230.3, the inner race 230.3 can be non-rotatably mounted on the pin130′, or can be mounted in a sliding manner, or can slide, thereon.

FIGS. 53A, 53B show an interface of a surgical instrument according toanother embodiment of the present invention, in various positions. Thiscorresponds substantially to the embodiments described above, such thatreference is made here to their description, and only the differencesshall be addressed below.

In the embodiment in FIGS. 53A-53B, the O-shaped closed groove 33″ inthe input drive element 32″ is designed such that it is asymmetric tothe rotational axis of the output drive link 31″ (perpendicular to theimage plane in FIG. 53), and the displacement axis B″ of the input driveelement 32″, and extends substantially only as far as this rotationalaxis.

As a result, the output drive link 31″ and the input drive link 32″ areclearly coupled to one another. If one imagines, on the contrary, thegroove 33″ extending (toward the left in FIG. 53) beyond the rotationalaxis, in particular symmetrical thereto, it is clear that the guideelement 30″ could then engage, in each case in two rotational positionsthat are symmetrical to the displacement axis B″, in the groove 33″. Asa result of an asymmetrical design of the groove 33′, this can beprevented, because, as a result, the guide element 30″ can engage in thegroove 33″ in exactly only one rotational position.

The series of figures, FIGS. 53A-53B again clearly illustrates thefunctional concept of the interface according to one embodiment of theinvention. If the output drive element 31″ rotates in the directionindicated in FIGS. 53A-53B by the movement arrow A″, the input drivelink 32″ coupled thereto is displaced in its thrust bearing (hatched inFIGS. 53A-53B) in its displacement axis B″. In order to limit thisdisplacement, in particular when the output drive link is decoupled, twoend stops 37.1, 37.2 are provided, which run on the front surfaces 32.1″or 32.2″, respectively, of the input drive links.

The (full) stroke H of the input drive link is obtained, when the outputdrive link is decoupled, by means of the spacing of the end stops 37.1,37.2, based on the spacings B of the front surfaces 32.1″ or 32.2″ to amid-line of the groove 33″. As a result, in one embodiment of thepresent invention, for which the depiction in FIGS. 53A-53B show only apossible embodiment, in general, a spacing B of a front surface of theinput drive link from a mid-line of the groove in the input drive linkis at least equal to the full stroke plus half of the groove width,having the reference symbols in FIGS. 53A-53B:

B≧H+D/2

where

-   -   B: spacing of a front surface of the input drive link to a        mid-line of the groove;    -   H: entire stroke of the input drive link; and    -   D: groove width.

FIG. 54 shows an interface of a surgical instrument according to anotherembodiment of the present invention. This corresponds substantially tothe embodiments explained above, such that reference is made here totheir descriptions, and only the differences shall be addressed below.

In the embodiment in FIG. 54, a sterile barrier 35 is disposed betweenthe guide element 30 of the output drive link 31 of the input drivemodule 25, which engages in the groove 33 of the input drive link 32guided in the displacement axis B on the thrust bearing 34 of theinstrument shaft 20, in order to convert a rotational movement A of theguide element 30 into a translational displacement of the input drivelink 32. This can also be provided in the embodiments in FIGS. 47-53explained above, without being shown therein.

FIGS. 55A-55E show an interface of a surgical instrument according to afurther embodiment of the present invention, in a view from above, inthe direction of a displacement axis (FIGS. 55A-55C), or in aperspective view (FIGS. 55D-55E), wherein the output drive link and theinput drive link are not coupled to one another (FIGS. 55A-55B) or arecoupled to one another (FIG. 55C). This corresponds substantially to theembodiments explained above, in particular in accordance with FIG. 48,such that reference is made here to the descriptions of the precedingembodiments, and only the differences shall be addressed below.

In the embodiment in FIGS. 55A-55E, the input drive link 32′ is guidedin a thrust bearing 34′ with a great deal of play, in particular, in aloose manner, such that it can be displaced on the instrument shaft. Inaddition, it is displaceably guided in a thrust bearing 340 having lessplay, in particular at least substantially without play, on the actuator31′ of the input drive module, when this input drive module is connectedto the instrument shaft (cf. FIG. 55C). In the connected state, the lessprecise guidance on the instrument shaft is thus non-functional. As aresult, the more complex, precise guidance is shifted to the input drivemodule, and thus the instrument shaft can be, or is, designed in asimpler and/or less expensive manner, in particular such that it canmore readily be sterilized and/or is a disposable article. As soon asthe instrument shaft and the input drive module are connected, the inputdrive module assumes the—more precise—guidance of the input drive link.

LIST OF REFERENCE SYMBOLS In the FIGS. 1 to 33

-   1 drive unit-   2 instrument shaft-   3 sterile barrier-   3.1 compensation element-   3.2 corrugated membrane (pre-tensioned cuff)-   3.3 corrugated bellows (pre-tensioned cuff)-   3.4 elastomer sleeve (cuff)-   3.5 translationally displaceable seal-   3.6 sterile extension-   3.7 reinforcement-   4 adapter (attachment element)-   10A, 10B output drive element (output drive assembly)-   10C coupling means-   10D guide rail-   11 output drive element base-   20A, 20B input drive element (input drive assembly)-   20C coupling means-   20D rotational thrust bearing-   20E gear toothing-   21 input drive element base-   30 roller-   40 coupling rod-   50 spring-   60 pull cable-   100 pin-   100.1 extension sleeve/tension lever (elastic/separate element)-   100.2 threaded spindle/actuating stud (clamping means)-   100.3 electric motor-   100.4 spindle nut-   100.5 thrust bearing-   100.6 locking balls-   100.7 intermediate element (assembly)-   100.8 cage sleeve-   200 coupling socket with cut-out (input drive element)-   200.1 compression spring-   1000 tilt lever (output drive/input drive element)-   2000 coupling part (input drive/output drive element)-   2000.1 thrust bearing

In the FIGS. 34 to 36

-   2.1, 2.2 blade (end effector)-   3 control means-   4 sterile barrier-   5 spring-   10 input drive module-   11, 12 tappet ((input drive module-side) drive train (assembly))-   13 electric motor (input drive)-   20 instrument shaft-   21, 22 tappet ((instrument shaft-side) drive train (assembly))-   31-34 strain metering strip (metering means, metering assembly)-   F_(E1), F_(E2) clamping force-   F_(S1), F_(S2) instrument shaft tappet force-   F₁, F₂ input drive module tappet force-   q₁ (rotational) degree of freedom-   S1 method step-   U_(A) bridge output voltage-   U_(E) supply voltage

In the FIGS. 37 to 46B

-   30 drive unit-   31 instrument shaft-   32 (flexible) sterile barrier-   34, 35 output drive tappet-   37, 38 input drive tappet-   40 robot-   41 (sterile) casing-   42 interface-   44; 44 a, 44 b electric motor-   45 a-45 d pair of tappets-   45.1 output drive link assembly-   45.2 input drive link assembly-   46; 46 a, 46 b spring element (compression spring)-   47; 47 a, 47 b input drive module-   47.1 housing for the input drive module-   49 housing-   53 instrument shaft housing-   54 tube-   55 pivot bearing-   56 a, 56 b interface-   57.1, 57.2, 57 a-57 d cable pull drum-   58 gearing wheel-   59 rocker-   60 (mechanical) stop-   61, 167 latch-   80 mounting element-   100, 103 electromagnet-   101, 104 permanent magnet-   102 spacing element-   105 spacing element-   106 counter-stop-   140 insertion opening-   142, 143, 164 recess-   150 cut-out-   151, 153 projection-   152, 160, 166 guide groove-   161, 165 guide rib-   170 lid-   180 a, 180 b section/converging surface-   181 a, 181 b moveable roller

In the FIGS. 47 to 55D

-   20; 20′; 120 instrument shaft-   21 end effector-   22 tube-   23 instrument housing-   24 interface-   25; 25′; 125 input drive module-   30; 30′; 30″; 130; 330 guide element-   31 output drive link-   31′; 31″; 131 electric motor gearing unit (actuator)-   32; 32′; 32″; 132; 132′; 132″ input drive link-   32.1″; 32.2″ front surface-   33; 33′; 33″ groove-   34; 34′ thrust bearing-   35 sterile barrier-   36; 136 pull cable/push rod-   37.1, 37.2 end stop-   130.1 bearing race (roller body)-   130.2 bearing race (tolerance element)-   130′ pin-   132.3 tolerance element-   132.4 spring element-   138 connecting member-   139 frame-   140 radial bearing-   230.3 inner race-   230.4 spring element-   233.1, 233.2 chamfers-   330.1, 330.2 roller bearing-   333.1 leg (integral tolerance element)-   333.2 groove-   333.3 hollow chamber-   340 thrust bearing-   A; A′; A″; A′″ rotational movement-   B; B′; B″; B″; B^(IV) displacement axis

What is claimed is:
 1. An instrument shaft having an input drive linkassembly with at least one moveable input drive link for actuating adegree of freedom of the instrument shaft, which projects, at leastsubstantially, perpendicular to a longitudinal axis of the instrumentshaft, extending to a mounting element on the instrument shaft for adrive unit.
 2. The instrument shaft according to claim 1, wherein themounting element has a guide and/or an insertion opening, in particulara lidded insertion opening, for inserting a drive unit in an insertiondirection, which is, in particular, at least substantially,perpendicular or parallel to the longitudinal axis of the instrumentshaft.
 3. The instrument shaft according to claim 1, wherein themounting element can be moved, in particular pivoted, in relation to alongitudinal axis of the instrument shaft.
 4. The instrument shaftaccording to claim 1, wherein the input drive link assembly is disposedin a recess.
 5. A surgical instrument comprising an instrument shaftaccording to claim 1; and a drive unit that can be releasably connectedto the instrument shaft.
 6. The surgical instrument according to claim5, wherein a coupling direction, in which an input drive module ismoveably mounted and pre-tensioned in a housing for the drive unit formsan angle with the longitudinal axis of the instrument shaft, which isgreater than 0 degrees, in particular is greater than 45 degrees, inparticular is at least substantially 90 degrees.
 7. The surgicalinstrument according to claim 6, further comprising a drive unit lockingassembly for locking the drive unit in place on a mounting element ofthe instrument shaft.
 8. The surgical instrument according to claim 5,further comprising an interface for the attachment thereof to a robot.9. A drive unit with a housing and at least one input drive module witha drive and an output drive link assembly with at least one moveableoutput drive link for actuating a degree of freedom of an instrumentshaft, which is moveably mounted and pre-tensioned in the housing in acoupling direction.
 10. The drive unit according to claim 9, furthercomprising a magnet assembly for pre-tensioning the input drive modulein the coupling direction.
 11. The drive unit according to claim 9,further comprising a retraction assembly, in particular a mechanicaland/or magnetic retraction assembly, for retracting the input drivemodule against the pre-tensioning.
 12. The drive unit according to claim11, further comprising an input drive module locking assembly forlocking the retracted input drive module in place.
 13. The drive unitaccording to claim 11, wherein the retraction assembly can be actuatedby a drive in the input drive module.
 14. The drive unit according toclaim 9, further comprising a positive driving means, in particular aconcave and/or moveable positive driving means, for positively drivingan input drive link assembly of an instrument shaft when inserting thedrive unit in a mounting element of the instrument shaft.
 15. The driveunit according to claim 9, wherein the output drive link assembly isdisposed in a recess.